parse_clause.c File Reference

#include "postgres.h"
#include "access/htup_details.h"
#include "access/nbtree.h"
#include "access/table.h"
#include "access/tsmapi.h"
#include "catalog/catalog.h"
#include "catalog/pg_am.h"
#include "catalog/pg_amproc.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/optimizer.h"
#include "parser/analyze.h"
#include "parser/parse_clause.h"
#include "parser/parse_coerce.h"
#include "parser/parse_collate.h"
#include "parser/parse_expr.h"
#include "parser/parse_func.h"
#include "parser/parse_oper.h"
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "parser/parse_type.h"
#include "parser/parser.h"
#include "rewrite/rewriteManip.h"
#include "utils/builtins.h"
#include "utils/catcache.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"

Include dependency graph for parse_clause.c:

Go to the source code of this file.

Functions
static int	extractRemainingColumns (ParseState *pstate, ParseNamespaceColumn *src_nscolumns, List *src_colnames, List **src_colnos, List **res_colnames, List **res_colvars, ParseNamespaceColumn *res_nscolumns)
static Node *	transformJoinUsingClause (ParseState *pstate, List *leftVars, List *rightVars)
static Node *	transformJoinOnClause (ParseState *pstate, JoinExpr *j, List *namespace)
static ParseNamespaceItem *	transformTableEntry (ParseState *pstate, RangeVar *r)
static ParseNamespaceItem *	transformRangeSubselect (ParseState *pstate, RangeSubselect *r)
static ParseNamespaceItem *	transformRangeFunction (ParseState *pstate, RangeFunction *r)
static ParseNamespaceItem *	transformRangeTableFunc (ParseState *pstate, RangeTableFunc *rtf)
static TableSampleClause *	transformRangeTableSample (ParseState *pstate, RangeTableSample *rts)
static ParseNamespaceItem *	getNSItemForSpecialRelationTypes (ParseState *pstate, RangeVar *rv)
static Node *	transformFromClauseItem (ParseState *pstate, Node *n, ParseNamespaceItem **top_nsitem, List **namespace)
static Var *	buildVarFromNSColumn (ParseState *pstate, ParseNamespaceColumn *nscol)
static Node *	buildMergedJoinVar (ParseState *pstate, JoinType jointype, Var *l_colvar, Var *r_colvar)
static void	markRelsAsNulledBy (ParseState *pstate, Node *n, int jindex)
static void	setNamespaceColumnVisibility (List *namespace, bool cols_visible)
static void	setNamespaceLateralState (List *namespace, bool lateral_only, bool lateral_ok)
static void	checkExprIsVarFree (ParseState *pstate, Node *n, const char *constructName)
static TargetEntry *	findTargetlistEntrySQL92 (ParseState *pstate, Node *node, List **tlist, ParseExprKind exprKind)
static TargetEntry *	findTargetlistEntrySQL99 (ParseState *pstate, Node *node, List **tlist, ParseExprKind exprKind)
static int	get_matching_location (int sortgroupref, List *sortgrouprefs, List *exprs)
static List *	resolve_unique_index_expr (ParseState *pstate, InferClause *infer, Relation heapRel)
static List *	addTargetToGroupList (ParseState *pstate, TargetEntry *tle, List *grouplist, List *targetlist, int location)
static WindowClause *	findWindowClause (List *wclist, const char *name)
static Node *	transformFrameOffset (ParseState *pstate, int frameOptions, Oid rangeopfamily, Oid rangeopcintype, Oid *inRangeFunc, Node *clause)
void	transformFromClause (ParseState *pstate, List *frmList)
int	setTargetTable (ParseState *pstate, RangeVar *relation, bool inh, bool alsoSource, AclMode requiredPerms)
Node *	transformWhereClause (ParseState *pstate, Node *clause, ParseExprKind exprKind, const char *constructName)
Node *	transformLimitClause (ParseState *pstate, Node *clause, ParseExprKind exprKind, const char *constructName, LimitOption limitOption)
static void	checkTargetlistEntrySQL92 (ParseState *pstate, TargetEntry *tle, ParseExprKind exprKind)
static Node *	flatten_grouping_sets (Node *expr, bool toplevel, bool *hasGroupingSets)
static Index	transformGroupClauseExpr (List **flatresult, Bitmapset *seen_local, ParseState *pstate, Node *gexpr, List **targetlist, List *sortClause, ParseExprKind exprKind, bool useSQL99, bool toplevel)
static List *	transformGroupClauseList (List **flatresult, ParseState *pstate, List *list, List **targetlist, List *sortClause, ParseExprKind exprKind, bool useSQL99, bool toplevel)
static Node *	transformGroupingSet (List **flatresult, ParseState *pstate, GroupingSet *gset, List **targetlist, List *sortClause, ParseExprKind exprKind, bool useSQL99, bool toplevel)
List *	transformGroupClause (ParseState *pstate, List *grouplist, List **groupingSets, List **targetlist, List *sortClause, ParseExprKind exprKind, bool useSQL99)
List *	transformSortClause (ParseState *pstate, List *orderlist, List **targetlist, ParseExprKind exprKind, bool useSQL99)
List *	transformWindowDefinitions (ParseState *pstate, List *windowdefs, List **targetlist)
List *	transformDistinctClause (ParseState *pstate, List **targetlist, List *sortClause, bool is_agg)
List *	transformDistinctOnClause (ParseState *pstate, List *distinctlist, List **targetlist, List *sortClause)
void	transformOnConflictArbiter (ParseState *pstate, OnConflictClause *onConflictClause, List **arbiterExpr, Node **arbiterWhere, Oid *constraint)
List *	addTargetToSortList (ParseState *pstate, TargetEntry *tle, List *sortlist, List *targetlist, SortBy *sortby)
Index	assignSortGroupRef (TargetEntry *tle, List *tlist)
bool	targetIsInSortList (TargetEntry *tle, Oid sortop, List *sortList)

Function Documentation

addTargetToGroupList()

static List * addTargetToGroupList ( ParseState *  pstate, TargetEntry *  tle, List *  grouplist, List *  targetlist, int  location  )

static

Definition at line 3537 of file parse_clause.c.

{
    Oid         restype = exprType((Node *) tle->expr);
 
    /* if tlist item is an UNKNOWN literal, change it to TEXT */
    if (restype == UNKNOWNOID)
    {
        tle->expr = (Expr *) coerce_type(pstate, (Node *) tle->expr,
                                         restype, TEXTOID, -1,
                                         COERCION_IMPLICIT,
                                         COERCE_IMPLICIT_CAST,
                                         -1);
        restype = TEXTOID;
    }
 
    /* avoid making duplicate grouplist entries */
    if (!targetIsInSortList(tle, InvalidOid, grouplist))
    {
        SortGroupClause *grpcl = makeNode(SortGroupClause);
        Oid         sortop;
        Oid         eqop;
        bool        hashable;
        ParseCallbackState pcbstate;
 
        setup_parser_errposition_callback(&pcbstate, pstate, location);
 
        /* determine the eqop and optional sortop */
        get_sort_group_operators(restype,
                                 false, true, false,
                                 &sortop, &eqop, NULL,
                                 &hashable);
 
        cancel_parser_errposition_callback(&pcbstate);
 
        grpcl->tleSortGroupRef = assignSortGroupRef(tle, targetlist);
        grpcl->eqop = eqop;
        grpcl->sortop = sortop;
        grpcl->reverse_sort = false;    /* sortop is "less than", or
                                         * InvalidOid */
        grpcl->nulls_first = false; /* OK with or without sortop */
        grpcl->hashable = hashable;
 
        grouplist = lappend(grouplist, grpcl);
    }
 
    return grouplist;
}

References assignSortGroupRef(), cancel_parser_errposition_callback(), COERCE_IMPLICIT_CAST, coerce_type(), COERCION_IMPLICIT, SortGroupClause::eqop, TargetEntry::expr, exprType(), get_sort_group_operators(), InvalidOid, lappend(), makeNode, SortGroupClause::nulls_first, SortGroupClause::reverse_sort, setup_parser_errposition_callback(), SortGroupClause::sortop, targetIsInSortList(), and SortGroupClause::tleSortGroupRef.

Referenced by transformDistinctClause(), transformDistinctOnClause(), and transformGroupClauseExpr().

addTargetToSortList()

List * addTargetToSortList	(	ParseState *	pstate,
		TargetEntry *	tle,
		List *	sortlist,
		List *	targetlist,
		SortBy *	sortby
	)

Definition at line 3393 of file parse_clause.c.

{
    Oid         restype = exprType((Node *) tle->expr);
    Oid         sortop;
    Oid         eqop;
    bool        hashable;
    bool        reverse;
    int         location;
    ParseCallbackState pcbstate;
 
    /* if tlist item is an UNKNOWN literal, change it to TEXT */
    if (restype == UNKNOWNOID)
    {
        tle->expr = (Expr *) coerce_type(pstate, (Node *) tle->expr,
                                         restype, TEXTOID, -1,
                                         COERCION_IMPLICIT,
                                         COERCE_IMPLICIT_CAST,
                                         -1);
        restype = TEXTOID;
    }
 
    /*
     * Rather than clutter the API of get_sort_group_operators and the other
     * functions we're about to use, make use of error context callback to
     * mark any error reports with a parse position.  We point to the operator
     * location if present, else to the expression being sorted.  (NB: use the
     * original untransformed expression here; the TLE entry might well point
     * at a duplicate expression in the regular SELECT list.)
     */
    location = sortby->location;
    if (location < 0)
        location = exprLocation(sortby->node);
    setup_parser_errposition_callback(&pcbstate, pstate, location);
 
    /* determine the sortop, eqop, and directionality */
    switch (sortby->sortby_dir)
    {
        case SORTBY_DEFAULT:
        case SORTBY_ASC:
            get_sort_group_operators(restype,
                                     true, true, false,
                                     &sortop, &eqop, NULL,
                                     &hashable);
            reverse = false;
            break;
        case SORTBY_DESC:
            get_sort_group_operators(restype,
                                     false, true, true,
                                     NULL, &eqop, &sortop,
                                     &hashable);
            reverse = true;
            break;
        case SORTBY_USING:
            Assert(sortby->useOp != NIL);
            sortop = compatible_oper_opid(sortby->useOp,
                                          restype,
                                          restype,
                                          false);
 
            /*
             * Verify it's a valid ordering operator, fetch the corresponding
             * equality operator, and determine whether to consider it like
             * ASC or DESC.
             */
            eqop = get_equality_op_for_ordering_op(sortop, &reverse);
            if (!OidIsValid(eqop))
                ereport(ERROR,
                        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                         errmsg("operator %s is not a valid ordering operator",
                                strVal(llast(sortby->useOp))),
                         errhint("Ordering operators must be \"<\" or \">\" members of btree operator families.")));
 
            /*
             * Also see if the equality operator is hashable.
             */
            hashable = op_hashjoinable(eqop, restype);
            break;
        default:
            elog(ERROR, "unrecognized sortby_dir: %d", sortby->sortby_dir);
            sortop = InvalidOid;    /* keep compiler quiet */
            eqop = InvalidOid;
            hashable = false;
            reverse = false;
            break;
    }
 
    cancel_parser_errposition_callback(&pcbstate);
 
    /* avoid making duplicate sortlist entries */
    if (!targetIsInSortList(tle, sortop, sortlist))
    {
        SortGroupClause *sortcl = makeNode(SortGroupClause);
 
        sortcl->tleSortGroupRef = assignSortGroupRef(tle, targetlist);
 
        sortcl->eqop = eqop;
        sortcl->sortop = sortop;
        sortcl->hashable = hashable;
        sortcl->reverse_sort = reverse;
 
        switch (sortby->sortby_nulls)
        {
            case SORTBY_NULLS_DEFAULT:
                /* NULLS FIRST is default for DESC; other way for ASC */
                sortcl->nulls_first = reverse;
                break;
            case SORTBY_NULLS_FIRST:
                sortcl->nulls_first = true;
                break;
            case SORTBY_NULLS_LAST:
                sortcl->nulls_first = false;
                break;
            default:
                elog(ERROR, "unrecognized sortby_nulls: %d",
                     sortby->sortby_nulls);
                break;
        }
 
        sortlist = lappend(sortlist, sortcl);
    }
 
    return sortlist;
}

References Assert, assignSortGroupRef(), cancel_parser_errposition_callback(), COERCE_IMPLICIT_CAST, coerce_type(), COERCION_IMPLICIT, compatible_oper_opid(), elog, SortGroupClause::eqop, ereport, errcode(), errhint(), errmsg(), ERROR, TargetEntry::expr, exprLocation(), exprType(), get_equality_op_for_ordering_op(), get_sort_group_operators(), InvalidOid, lappend(), llast, SortBy::location, makeNode, NIL, SortBy::node, SortGroupClause::nulls_first, OidIsValid, op_hashjoinable(), SortGroupClause::reverse_sort, setup_parser_errposition_callback(), SORTBY_ASC, SORTBY_DEFAULT, SORTBY_DESC, SortBy::sortby_dir, SortBy::sortby_nulls, SORTBY_NULLS_DEFAULT, SORTBY_NULLS_FIRST, SORTBY_NULLS_LAST, SORTBY_USING, SortGroupClause::sortop, strVal, targetIsInSortList(), SortGroupClause::tleSortGroupRef, and SortBy::useOp.

Referenced by transformAggregateCall(), and transformSortClause().

assignSortGroupRef()

Index assignSortGroupRef	(	TargetEntry *	tle,
		List *	tlist
	)

Definition at line 3594 of file parse_clause.c.

{
    Index       maxRef;
    ListCell   *l;
 
    if (tle->ressortgroupref)   /* already has one? */
        return tle->ressortgroupref;
 
    /* easiest way to pick an unused refnumber: max used + 1 */
    maxRef = 0;
    foreach(l, tlist)
    {
        Index       ref = ((TargetEntry *) lfirst(l))->ressortgroupref;
 
        if (ref > maxRef)
            maxRef = ref;
    }
    tle->ressortgroupref = maxRef + 1;
    return tle->ressortgroupref;
}

References lfirst, and TargetEntry::ressortgroupref.

Referenced by addTargetToGroupList(), addTargetToSortList(), build_minmax_path(), create_unique_plan(), generate_setop_child_grouplist(), and transformDistinctOnClause().

buildMergedJoinVar()

static Node * buildMergedJoinVar ( ParseState *  pstate, JoinType  jointype, Var *  l_colvar, Var *  r_colvar  )

static

Definition at line 1666 of file parse_clause.c.

{
    Oid         outcoltype;
    int32       outcoltypmod;
    Node       *l_node,
               *r_node,
               *res_node;
 
    outcoltype = select_common_type(pstate,
                                    list_make2(l_colvar, r_colvar),
                                    "JOIN/USING",
                                    NULL);
    outcoltypmod = select_common_typmod(pstate,
                                        list_make2(l_colvar, r_colvar),
                                        outcoltype);
 
    /*
     * Insert coercion functions if needed.  Note that a difference in typmod
     * can only happen if input has typmod but outcoltypmod is -1. In that
     * case we insert a RelabelType to clearly mark that result's typmod is
     * not same as input.  We never need coerce_type_typmod.
     */
    if (l_colvar->vartype != outcoltype)
        l_node = coerce_type(pstate, (Node *) l_colvar, l_colvar->vartype,
                             outcoltype, outcoltypmod,
                             COERCION_IMPLICIT, COERCE_IMPLICIT_CAST, -1);
    else if (l_colvar->vartypmod != outcoltypmod)
        l_node = (Node *) makeRelabelType((Expr *) l_colvar,
                                          outcoltype, outcoltypmod,
                                          InvalidOid,   /* fixed below */
                                          COERCE_IMPLICIT_CAST);
    else
        l_node = (Node *) l_colvar;
 
    if (r_colvar->vartype != outcoltype)
        r_node = coerce_type(pstate, (Node *) r_colvar, r_colvar->vartype,
                             outcoltype, outcoltypmod,
                             COERCION_IMPLICIT, COERCE_IMPLICIT_CAST, -1);
    else if (r_colvar->vartypmod != outcoltypmod)
        r_node = (Node *) makeRelabelType((Expr *) r_colvar,
                                          outcoltype, outcoltypmod,
                                          InvalidOid,   /* fixed below */
                                          COERCE_IMPLICIT_CAST);
    else
        r_node = (Node *) r_colvar;
 
    /*
     * Choose what to emit
     */
    switch (jointype)
    {
        case JOIN_INNER:
 
            /*
             * We can use either var; prefer non-coerced one if available.
             */
            if (IsA(l_node, Var))
                res_node = l_node;
            else if (IsA(r_node, Var))
                res_node = r_node;
            else
                res_node = l_node;
            break;
        case JOIN_LEFT:
            /* Always use left var */
            res_node = l_node;
            break;
        case JOIN_RIGHT:
            /* Always use right var */
            res_node = r_node;
            break;
        case JOIN_FULL:
            {
                /*
                 * Here we must build a COALESCE expression to ensure that the
                 * join output is non-null if either input is.
                 */
                CoalesceExpr *c = makeNode(CoalesceExpr);
 
                c->coalescetype = outcoltype;
                /* coalescecollid will get set below */
                c->args = list_make2(l_node, r_node);
                c->location = -1;
                res_node = (Node *) c;
                break;
            }
        default:
            elog(ERROR, "unrecognized join type: %d", (int) jointype);
            res_node = NULL;    /* keep compiler quiet */
            break;
    }
 
    /*
     * Apply assign_expr_collations to fix up the collation info in the
     * coercion and CoalesceExpr nodes, if we made any.  This must be done now
     * so that the join node's alias vars show correct collation info.
     */
    assign_expr_collations(pstate, res_node);
 
    return res_node;
}

References assign_expr_collations(), COERCE_IMPLICIT_CAST, coerce_type(), COERCION_IMPLICIT, elog, ERROR, InvalidOid, IsA, JOIN_FULL, JOIN_INNER, JOIN_LEFT, JOIN_RIGHT, list_make2, makeNode, makeRelabelType(), select_common_type(), and select_common_typmod().

Referenced by transformFromClauseItem().

buildVarFromNSColumn()

static Var * buildVarFromNSColumn ( ParseState *  pstate, ParseNamespaceColumn *  nscol  )

static

Definition at line 1639 of file parse_clause.c.

{
    Var        *var;
 
    Assert(nscol->p_varno > 0); /* i.e., not deleted column */
    var = makeVar(nscol->p_varno,
                  nscol->p_varattno,
                  nscol->p_vartype,
                  nscol->p_vartypmod,
                  nscol->p_varcollid,
                  0);
    /* makeVar doesn't offer parameters for these, so set by hand: */
    var->varreturningtype = nscol->p_varreturningtype;
    var->varnosyn = nscol->p_varnosyn;
    var->varattnosyn = nscol->p_varattnosyn;
 
    /* ... and update varnullingrels */
    markNullableIfNeeded(pstate, var);
 
    return var;
}

References Assert, makeVar(), markNullableIfNeeded(), ParseNamespaceColumn::p_varattno, ParseNamespaceColumn::p_varattnosyn, ParseNamespaceColumn::p_varcollid, ParseNamespaceColumn::p_varno, ParseNamespaceColumn::p_varnosyn, ParseNamespaceColumn::p_varreturningtype, ParseNamespaceColumn::p_vartype, ParseNamespaceColumn::p_vartypmod, and Var::varreturningtype.

Referenced by extractRemainingColumns(), and transformFromClauseItem().

checkExprIsVarFree()

static void checkExprIsVarFree ( ParseState *  pstate, Node *  n, const char *  constructName  )

static

Definition at line 1925 of file parse_clause.c.

{
    if (contain_vars_of_level(n, 0))
    {
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
        /* translator: %s is name of a SQL construct, eg LIMIT */
                 errmsg("argument of %s must not contain variables",
                        constructName),
                 parser_errposition(pstate,
                                    locate_var_of_level(n, 0))));
    }
}

References contain_vars_of_level(), ereport, errcode(), errmsg(), ERROR, locate_var_of_level(), and parser_errposition().

Referenced by transformFrameOffset(), and transformLimitClause().

checkTargetlistEntrySQL92()

static void checkTargetlistEntrySQL92 ( ParseState *  pstate, TargetEntry *  tle, ParseExprKind  exprKind  )

static

Definition at line 1950 of file parse_clause.c.

{
    switch (exprKind)
    {
        case EXPR_KIND_GROUP_BY:
            /* reject aggregates and window functions */
            if (pstate->p_hasAggs &&
                contain_aggs_of_level((Node *) tle->expr, 0))
                ereport(ERROR,
                        (errcode(ERRCODE_GROUPING_ERROR),
                /* translator: %s is name of a SQL construct, eg GROUP BY */
                         errmsg("aggregate functions are not allowed in %s",
                                ParseExprKindName(exprKind)),
                         parser_errposition(pstate,
                                            locate_agg_of_level((Node *) tle->expr, 0))));
            if (pstate->p_hasWindowFuncs &&
                contain_windowfuncs((Node *) tle->expr))
                ereport(ERROR,
                        (errcode(ERRCODE_WINDOWING_ERROR),
                /* translator: %s is name of a SQL construct, eg GROUP BY */
                         errmsg("window functions are not allowed in %s",
                                ParseExprKindName(exprKind)),
                         parser_errposition(pstate,
                                            locate_windowfunc((Node *) tle->expr))));
            break;
        case EXPR_KIND_ORDER_BY:
            /* no extra checks needed */
            break;
        case EXPR_KIND_DISTINCT_ON:
            /* no extra checks needed */
            break;
        default:
            elog(ERROR, "unexpected exprKind in checkTargetlistEntrySQL92");
            break;
    }
}

References contain_aggs_of_level(), contain_windowfuncs(), elog, ereport, errcode(), errmsg(), ERROR, TargetEntry::expr, EXPR_KIND_DISTINCT_ON, EXPR_KIND_GROUP_BY, EXPR_KIND_ORDER_BY, locate_agg_of_level(), locate_windowfunc(), ParseState::p_hasAggs, ParseState::p_hasWindowFuncs, ParseExprKindName(), and parser_errposition().

Referenced by findTargetlistEntrySQL92().

extractRemainingColumns()

static int extractRemainingColumns ( ParseState *  pstate, ParseNamespaceColumn *  src_nscolumns, List *  src_colnames, List **  src_colnos, List **  res_colnames, List **  res_colvars, ParseNamespaceColumn *  res_nscolumns  )

static

Definition at line 253 of file parse_clause.c.

{
    int         colcount = 0;
    Bitmapset  *prevcols;
    int         attnum;
    ListCell   *lc;
 
    /*
     * While we could just test "list_member_int(*src_colnos, attnum)" to
     * detect already-merged columns in the loop below, that would be O(N^2)
     * for a wide input table.  Instead build a bitmapset of just the merged
     * USING columns, which we won't add to within the main loop.
     */
    prevcols = NULL;
    foreach(lc, *src_colnos)
    {
        prevcols = bms_add_member(prevcols, lfirst_int(lc));
    }
 
    attnum = 0;
    foreach(lc, src_colnames)
    {
        char       *colname = strVal(lfirst(lc));
 
        attnum++;
        /* Non-dropped and not already merged? */
        if (colname[0] != '\0' && !bms_is_member(attnum, prevcols))
        {
            /* Yes, so emit it as next output column */
            *src_colnos = lappend_int(*src_colnos, attnum);
            *res_colnames = lappend(*res_colnames, lfirst(lc));
            *res_colvars = lappend(*res_colvars,
                                   buildVarFromNSColumn(pstate,
                                                        src_nscolumns + attnum - 1));
            /* Copy the input relation's nscolumn data for this column */
            res_nscolumns[colcount] = src_nscolumns[attnum - 1];
            colcount++;
        }
    }
    return colcount;
}

References attnum, bms_add_member(), bms_is_member(), buildVarFromNSColumn(), lappend(), lappend_int(), lfirst, lfirst_int, and strVal.

Referenced by transformFromClauseItem().

findTargetlistEntrySQL92()

static TargetEntry * findTargetlistEntrySQL92 ( ParseState *  pstate, Node *  node, List **  tlist, ParseExprKind  exprKind  )

static

Definition at line 2006 of file parse_clause.c.

{
    ListCell   *tl;
 
    /*----------
     * Handle two special cases as mandated by the SQL92 spec:
     *
     * 1. Bare ColumnName (no qualifier or subscripts)
     *    For a bare identifier, we search for a matching column name
     *    in the existing target list.  Multiple matches are an error
     *    unless they refer to identical values; for example,
     *    we allow  SELECT a, a FROM table ORDER BY a
     *    but not   SELECT a AS b, b FROM table ORDER BY b
     *    If no match is found, we fall through and treat the identifier
     *    as an expression.
     *    For GROUP BY, it is incorrect to match the grouping item against
     *    targetlist entries: according to SQL92, an identifier in GROUP BY
     *    is a reference to a column name exposed by FROM, not to a target
     *    list column.  However, many implementations (including pre-7.0
     *    PostgreSQL) accept this anyway.  So for GROUP BY, we look first
     *    to see if the identifier matches any FROM column name, and only
     *    try for a targetlist name if it doesn't.  This ensures that we
     *    adhere to the spec in the case where the name could be both.
     *    DISTINCT ON isn't in the standard, so we can do what we like there;
     *    we choose to make it work like ORDER BY, on the rather flimsy
     *    grounds that ordinary DISTINCT works on targetlist entries.
     *
     * 2. IntegerConstant
     *    This means to use the n'th item in the existing target list.
     *    Note that it would make no sense to order/group/distinct by an
     *    actual constant, so this does not create a conflict with SQL99.
     *    GROUP BY column-number is not allowed by SQL92, but since
     *    the standard has no other behavior defined for this syntax,
     *    we may as well accept this common extension.
     *
     * Note that pre-existing resjunk targets must not be used in either case,
     * since the user didn't write them in his SELECT list.
     *
     * If neither special case applies, fall through to treat the item as
     * an expression per SQL99.
     *----------
     */
    if (IsA(node, ColumnRef) &&
        list_length(((ColumnRef *) node)->fields) == 1 &&
        IsA(linitial(((ColumnRef *) node)->fields), String))
    {
        char       *name = strVal(linitial(((ColumnRef *) node)->fields));
        int         location = ((ColumnRef *) node)->location;
 
        if (exprKind == EXPR_KIND_GROUP_BY)
        {
            /*
             * In GROUP BY, we must prefer a match against a FROM-clause
             * column to one against the targetlist.  Look to see if there is
             * a matching column.  If so, fall through to use SQL99 rules.
             * NOTE: if name could refer ambiguously to more than one column
             * name exposed by FROM, colNameToVar will ereport(ERROR). That's
             * just what we want here.
             *
             * Small tweak for 7.4.3: ignore matches in upper query levels.
             * This effectively changes the search order for bare names to (1)
             * local FROM variables, (2) local targetlist aliases, (3) outer
             * FROM variables, whereas before it was (1) (3) (2). SQL92 and
             * SQL99 do not allow GROUPing BY an outer reference, so this
             * breaks no cases that are legal per spec, and it seems a more
             * self-consistent behavior.
             */
            if (colNameToVar(pstate, name, true, location) != NULL)
                name = NULL;
        }
 
        if (name != NULL)
        {
            TargetEntry *target_result = NULL;
 
            foreach(tl, *tlist)
            {
                TargetEntry *tle = (TargetEntry *) lfirst(tl);
 
                if (!tle->resjunk &&
                    strcmp(tle->resname, name) == 0)
                {
                    if (target_result != NULL)
                    {
                        if (!equal(target_result->expr, tle->expr))
                            ereport(ERROR,
                                    (errcode(ERRCODE_AMBIGUOUS_COLUMN),
 
                            /*------
                              translator: first %s is name of a SQL construct, eg ORDER BY */
                                     errmsg("%s \"%s\" is ambiguous",
                                            ParseExprKindName(exprKind),
                                            name),
                                     parser_errposition(pstate, location)));
                    }
                    else
                        target_result = tle;
                    /* Stay in loop to check for ambiguity */
                }
            }
            if (target_result != NULL)
            {
                /* return the first match, after suitable validation */
                checkTargetlistEntrySQL92(pstate, target_result, exprKind);
                return target_result;
            }
        }
    }
    if (IsA(node, A_Const))
    {
        A_Const    *aconst = castNode(A_Const, node);
        int         targetlist_pos = 0;
        int         target_pos;
 
        if (!IsA(&aconst->val, Integer))
            ereport(ERROR,
                    (errcode(ERRCODE_SYNTAX_ERROR),
            /* translator: %s is name of a SQL construct, eg ORDER BY */
                     errmsg("non-integer constant in %s",
                            ParseExprKindName(exprKind)),
                     parser_errposition(pstate, aconst->location)));
 
        target_pos = intVal(&aconst->val);
        foreach(tl, *tlist)
        {
            TargetEntry *tle = (TargetEntry *) lfirst(tl);
 
            if (!tle->resjunk)
            {
                if (++targetlist_pos == target_pos)
                {
                    /* return the unique match, after suitable validation */
                    checkTargetlistEntrySQL92(pstate, tle, exprKind);
                    return tle;
                }
            }
        }
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
        /* translator: %s is name of a SQL construct, eg ORDER BY */
                 errmsg("%s position %d is not in select list",
                        ParseExprKindName(exprKind), target_pos),
                 parser_errposition(pstate, aconst->location)));
    }
 
    /*
     * Otherwise, we have an expression, so process it per SQL99 rules.
     */
    return findTargetlistEntrySQL99(pstate, node, tlist, exprKind);
}

References castNode, checkTargetlistEntrySQL92(), colNameToVar(), equal(), ereport, errcode(), errmsg(), ERROR, TargetEntry::expr, EXPR_KIND_GROUP_BY, findTargetlistEntrySQL99(), intVal, IsA, lfirst, linitial, list_length(), A_Const::location, name, ParseExprKindName(), parser_errposition(), strVal, and A_Const::val.

Referenced by transformDistinctOnClause(), transformGroupClauseExpr(), and transformSortClause().

findTargetlistEntrySQL99()

static TargetEntry * findTargetlistEntrySQL99 ( ParseState *  pstate, Node *  node, List **  tlist, ParseExprKind  exprKind  )

static

Definition at line 2172 of file parse_clause.c.

{
    TargetEntry *target_result;
    ListCell   *tl;
    Node       *expr;
 
    /*
     * Convert the untransformed node to a transformed expression, and search
     * for a match in the tlist.  NOTE: it doesn't really matter whether there
     * is more than one match.  Also, we are willing to match an existing
     * resjunk target here, though the SQL92 cases above must ignore resjunk
     * targets.
     */
    expr = transformExpr(pstate, node, exprKind);
 
    foreach(tl, *tlist)
    {
        TargetEntry *tle = (TargetEntry *) lfirst(tl);
        Node       *texpr;
 
        /*
         * Ignore any implicit cast on the existing tlist expression.
         *
         * This essentially allows the ORDER/GROUP/etc item to adopt the same
         * datatype previously selected for a textually-equivalent tlist item.
         * There can't be any implicit cast at top level in an ordinary SELECT
         * tlist at this stage, but the case does arise with ORDER BY in an
         * aggregate function.
         */
        texpr = strip_implicit_coercions((Node *) tle->expr);
 
        if (equal(expr, texpr))
            return tle;
    }
 
    /*
     * If no matches, construct a new target entry which is appended to the
     * end of the target list.  This target is given resjunk = true so that it
     * will not be projected into the final tuple.
     */
    target_result = transformTargetEntry(pstate, node, expr, exprKind,
                                         NULL, true);
 
    *tlist = lappend(*tlist, target_result);
 
    return target_result;
}

References equal(), TargetEntry::expr, lappend(), lfirst, strip_implicit_coercions(), transformExpr(), and transformTargetEntry().

Referenced by findTargetlistEntrySQL92(), transformGroupClauseExpr(), and transformSortClause().

findWindowClause()

static WindowClause * findWindowClause ( List *  wclist, const char *  name  )

static

Definition at line 3662 of file parse_clause.c.

{
    ListCell   *l;
 
    foreach(l, wclist)
    {
        WindowClause *wc = (WindowClause *) lfirst(l);
 
        if (wc->name && strcmp(wc->name, name) == 0)
            return wc;
    }
 
    return NULL;
}

References lfirst, and name.

Referenced by transformWindowDefinitions().

flatten_grouping_sets()

static Node * flatten_grouping_sets ( Node *  expr, bool  toplevel, bool *  hasGroupingSets  )

static

Definition at line 2258 of file parse_clause.c.

{
    /* just in case of pathological input */
    check_stack_depth();
 
    if (expr == (Node *) NIL)
        return (Node *) NIL;
 
    switch (expr->type)
    {
        case T_RowExpr:
            {
                RowExpr    *r = (RowExpr *) expr;
 
                if (r->row_format == COERCE_IMPLICIT_CAST)
                    return flatten_grouping_sets((Node *) r->args,
                                                 false, NULL);
            }
            break;
        case T_GroupingSet:
            {
                GroupingSet *gset = (GroupingSet *) expr;
                ListCell   *l2;
                List       *result_set = NIL;
 
                if (hasGroupingSets)
                    *hasGroupingSets = true;
 
                /*
                 * at the top level, we skip over all empty grouping sets; the
                 * caller can supply the canonical GROUP BY () if nothing is
                 * left.
                 */
 
                if (toplevel && gset->kind == GROUPING_SET_EMPTY)
                    return (Node *) NIL;
 
                foreach(l2, gset->content)
                {
                    Node       *n1 = lfirst(l2);
                    Node       *n2 = flatten_grouping_sets(n1, false, NULL);
 
                    if (IsA(n1, GroupingSet) &&
                        ((GroupingSet *) n1)->kind == GROUPING_SET_SETS)
                        result_set = list_concat(result_set, (List *) n2);
                    else
                        result_set = lappend(result_set, n2);
                }
 
                /*
                 * At top level, keep the grouping set node; but if we're in a
                 * nested grouping set, then we need to concat the flattened
                 * result into the outer list if it's simply nested.
                 */
 
                if (toplevel || (gset->kind != GROUPING_SET_SETS))
                {
                    return (Node *) makeGroupingSet(gset->kind, result_set, gset->location);
                }
                else
                    return (Node *) result_set;
            }
        case T_List:
            {
                List       *result = NIL;
                ListCell   *l;
 
                foreach(l, (List *) expr)
                {
                    Node       *n = flatten_grouping_sets(lfirst(l), toplevel, hasGroupingSets);
 
                    if (n != (Node *) NIL)
                    {
                        if (IsA(n, List))
                            result = list_concat(result, (List *) n);
                        else
                            result = lappend(result, n);
                    }
                }
 
                return (Node *) result;
            }
        default:
            break;
    }
 
    return expr;
}

References RowExpr::args, check_stack_depth(), COERCE_IMPLICIT_CAST, GroupingSet::content, flatten_grouping_sets(), GROUPING_SET_EMPTY, GROUPING_SET_SETS, IsA, lappend(), lfirst, list_concat(), GroupingSet::location, makeGroupingSet(), NIL, and Node::type.

Referenced by flatten_grouping_sets(), and transformGroupClause().

get_matching_location()

static int get_matching_location ( int  sortgroupref, List *  sortgrouprefs, List *  exprs  )

static

Definition at line 3176 of file parse_clause.c.

{
    ListCell   *lcs;
    ListCell   *lce;
 
    forboth(lcs, sortgrouprefs, lce, exprs)
    {
        if (lfirst_int(lcs) == sortgroupref)
            return exprLocation((Node *) lfirst(lce));
    }
    /* if no match, caller blew it */
    elog(ERROR, "get_matching_location: no matching sortgroupref");
    return -1;                  /* keep compiler quiet */
}

References elog, ERROR, exprLocation(), forboth, lfirst, and lfirst_int.

Referenced by transformDistinctOnClause().

getNSItemForSpecialRelationTypes()

static ParseNamespaceItem * getNSItemForSpecialRelationTypes ( ParseState *  pstate, RangeVar *  rv  )

static

Definition at line 1011 of file parse_clause.c.

{
    ParseNamespaceItem *nsitem;
    CommonTableExpr *cte;
    Index       levelsup;
 
    /*
     * if it is a qualified name, it can't be a CTE or tuplestore reference
     */
    if (rv->schemaname)
        return NULL;
 
    cte = scanNameSpaceForCTE(pstate, rv->relname, &levelsup);
    if (cte)
        nsitem = addRangeTableEntryForCTE(pstate, cte, levelsup, rv, true);
    else if (scanNameSpaceForENR(pstate, rv->relname))
        nsitem = addRangeTableEntryForENR(pstate, rv, true);
    else
        nsitem = NULL;
 
    return nsitem;
}

References addRangeTableEntryForCTE(), addRangeTableEntryForENR(), RangeVar::relname, scanNameSpaceForCTE(), scanNameSpaceForENR(), and RangeVar::schemaname.

Referenced by transformFromClauseItem().

markRelsAsNulledBy()

static void markRelsAsNulledBy ( ParseState *  pstate, Node *  n, int  jindex  )

static

Definition at line 1774 of file parse_clause.c.

{
    int         varno;
    ListCell   *lc;
 
    /* Note: we can't see FromExpr here */
    if (IsA(n, RangeTblRef))
    {
        varno = ((RangeTblRef *) n)->rtindex;
    }
    else if (IsA(n, JoinExpr))
    {
        JoinExpr   *j = (JoinExpr *) n;
 
        /* recurse to children */
        markRelsAsNulledBy(pstate, j->larg, jindex);
        markRelsAsNulledBy(pstate, j->rarg, jindex);
        varno = j->rtindex;
    }
    else
    {
        elog(ERROR, "unrecognized node type: %d", (int) nodeTag(n));
        varno = 0;              /* keep compiler quiet */
    }
 
    /*
     * Now add jindex to the p_nullingrels set for relation varno.  Since we
     * maintain the p_nullingrels list lazily, we might need to extend it to
     * make the varno'th entry exist.
     */
    while (list_length(pstate->p_nullingrels) < varno)
        pstate->p_nullingrels = lappend(pstate->p_nullingrels, NULL);
    lc = list_nth_cell(pstate->p_nullingrels, varno - 1);
    lfirst(lc) = bms_add_member((Bitmapset *) lfirst(lc), jindex);
}

References bms_add_member(), elog, ERROR, IsA, j, lappend(), lfirst, list_length(), list_nth_cell(), markRelsAsNulledBy(), nodeTag, and ParseState::p_nullingrels.

Referenced by markRelsAsNulledBy(), and transformFromClauseItem().

resolve_unique_index_expr()

static List * resolve_unique_index_expr ( ParseState *  pstate, InferClause *  infer, Relation  heapRel  )

static

Definition at line 3201 of file parse_clause.c.

{
    List       *result = NIL;
    ListCell   *l;
 
    foreach(l, infer->indexElems)
    {
        IndexElem  *ielem = (IndexElem *) lfirst(l);
        InferenceElem *pInfer = makeNode(InferenceElem);
        Node       *parse;
 
        /*
         * Raw grammar re-uses CREATE INDEX infrastructure for unique index
         * inference clause, and so will accept opclasses by name and so on.
         *
         * Make no attempt to match ASC or DESC ordering or NULLS FIRST/NULLS
         * LAST ordering, since those are not significant for inference
         * purposes (any unique index matching the inference specification in
         * other regards is accepted indifferently).  Actively reject this as
         * wrong-headed.
         */
        if (ielem->ordering != SORTBY_DEFAULT)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
                     errmsg("ASC/DESC is not allowed in ON CONFLICT clause"),
                     parser_errposition(pstate,
                                        exprLocation((Node *) infer))));
        if (ielem->nulls_ordering != SORTBY_NULLS_DEFAULT)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
                     errmsg("NULLS FIRST/LAST is not allowed in ON CONFLICT clause"),
                     parser_errposition(pstate,
                                        exprLocation((Node *) infer))));
 
        if (!ielem->expr)
        {
            /* Simple index attribute */
            ColumnRef  *n;
 
            /*
             * Grammar won't have built raw expression for us in event of
             * plain column reference.  Create one directly, and perform
             * expression transformation.  Planner expects this, and performs
             * its own normalization for the purposes of matching against
             * pg_index.
             */
            n = makeNode(ColumnRef);
            n->fields = list_make1(makeString(ielem->name));
            /* Location is approximately that of inference specification */
            n->location = infer->location;
            parse = (Node *) n;
        }
        else
        {
            /* Do parse transformation of the raw expression */
            parse = (Node *) ielem->expr;
        }
 
        /*
         * transformExpr() will reject subqueries, aggregates, window
         * functions, and SRFs, based on being passed
         * EXPR_KIND_INDEX_EXPRESSION.  So we needn't worry about those
         * further ... not that they would match any available index
         * expression anyway.
         */
        pInfer->expr = transformExpr(pstate, parse, EXPR_KIND_INDEX_EXPRESSION);
 
        /* Perform lookup of collation and operator class as required */
        if (!ielem->collation)
            pInfer->infercollid = InvalidOid;
        else
            pInfer->infercollid = LookupCollation(pstate, ielem->collation,
                                                  exprLocation(pInfer->expr));
 
        if (!ielem->opclass)
            pInfer->inferopclass = InvalidOid;
        else
            pInfer->inferopclass = get_opclass_oid(BTREE_AM_OID,
                                                   ielem->opclass, false);
 
        result = lappend(result, pInfer);
    }
 
    return result;
}

References IndexElem::collation, ereport, errcode(), errmsg(), ERROR, IndexElem::expr, InferenceElem::expr, EXPR_KIND_INDEX_EXPRESSION, exprLocation(), ColumnRef::fields, get_opclass_oid(), InferClause::indexElems, InferenceElem::infercollid, InferenceElem::inferopclass, InvalidOid, lappend(), lfirst, list_make1, ColumnRef::location, LookupCollation(), makeNode, makeString(), IndexElem::name, NIL, IndexElem::nulls_ordering, IndexElem::opclass, IndexElem::ordering, parse(), parser_errposition(), SORTBY_DEFAULT, SORTBY_NULLS_DEFAULT, and transformExpr().

Referenced by transformOnConflictArbiter().

setNamespaceColumnVisibility()

static void setNamespaceColumnVisibility ( List *  namespace, bool  cols_visible  )

static

Definition at line 1815 of file parse_clause.c.

{
    ListCell   *lc;
 
    foreach(lc, namespace)
    {
        ParseNamespaceItem *nsitem = (ParseNamespaceItem *) lfirst(lc);
 
        nsitem->p_cols_visible = cols_visible;
    }
}

References lfirst, and ParseNamespaceItem::p_cols_visible.

Referenced by transformFromClauseItem().

setNamespaceLateralState()

static void setNamespaceLateralState ( List *  namespace, bool  lateral_only, bool  lateral_ok  )

static

Definition at line 1832 of file parse_clause.c.

{
    ListCell   *lc;
 
    foreach(lc, namespace)
    {
        ParseNamespaceItem *nsitem = (ParseNamespaceItem *) lfirst(lc);
 
        nsitem->p_lateral_only = lateral_only;
        nsitem->p_lateral_ok = lateral_ok;
    }
}

References lfirst, ParseNamespaceItem::p_lateral_ok, and ParseNamespaceItem::p_lateral_only.

Referenced by transformFromClause(), transformFromClauseItem(), and transformJoinOnClause().

setTargetTable()

int setTargetTable	(	ParseState *	pstate,
		RangeVar *	relation,
		bool	inh,
		bool	alsoSource,
		AclMode	requiredPerms
	)

Definition at line 178 of file parse_clause.c.

{
    ParseNamespaceItem *nsitem;
 
    /*
     * ENRs hide tables of the same name, so we need to check for them first.
     * In contrast, CTEs don't hide tables (for this purpose).
     */
    if (relation->schemaname == NULL &&
        scanNameSpaceForENR(pstate, relation->relname))
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("relation \"%s\" cannot be the target of a modifying statement",
                        relation->relname)));
 
    /* Close old target; this could only happen for multi-action rules */
    if (pstate->p_target_relation != NULL)
        table_close(pstate->p_target_relation, NoLock);
 
    /*
     * Open target rel and grab suitable lock (which we will hold till end of
     * transaction).
     *
     * free_parsestate() will eventually do the corresponding table_close(),
     * but *not* release the lock.
     */
    pstate->p_target_relation = parserOpenTable(pstate, relation,
                                                RowExclusiveLock);
 
    /*
     * Now build an RTE and a ParseNamespaceItem.
     */
    nsitem = addRangeTableEntryForRelation(pstate, pstate->p_target_relation,
                                           RowExclusiveLock,
                                           relation->alias, inh, false);
 
    /* remember the RTE/nsitem as being the query target */
    pstate->p_target_nsitem = nsitem;
 
    /*
     * Override addRangeTableEntry's default ACL_SELECT permissions check, and
     * instead mark target table as requiring exactly the specified
     * permissions.
     *
     * If we find an explicit reference to the rel later during parse
     * analysis, we will add the ACL_SELECT bit back again; see
     * markVarForSelectPriv and its callers.
     */
    nsitem->p_perminfo->requiredPerms = requiredPerms;
 
    /*
     * If UPDATE/DELETE, add table to joinlist and namespace.
     */
    if (alsoSource)
        addNSItemToQuery(pstate, nsitem, true, true, true);
 
    return nsitem->p_rtindex;
}

References addNSItemToQuery(), addRangeTableEntryForRelation(), RangeVar::alias, ereport, errcode(), errmsg(), ERROR, NoLock, ParseNamespaceItem::p_perminfo, ParseNamespaceItem::p_rtindex, ParseState::p_target_nsitem, ParseState::p_target_relation, parserOpenTable(), RangeVar::relname, RTEPermissionInfo::requiredPerms, RowExclusiveLock, scanNameSpaceForENR(), RangeVar::schemaname, and table_close().

Referenced by transformDeleteStmt(), transformInsertStmt(), transformMergeStmt(), and transformUpdateStmt().

targetIsInSortList()

bool targetIsInSortList	(	TargetEntry *	tle,
		Oid	sortop,
		List *	sortList
	)

Definition at line 3635 of file parse_clause.c.

{
    Index       ref = tle->ressortgroupref;
    ListCell   *l;
 
    /* no need to scan list if tle has no marker */
    if (ref == 0)
        return false;
 
    foreach(l, sortList)
    {
        SortGroupClause *scl = (SortGroupClause *) lfirst(l);
 
        if (scl->tleSortGroupRef == ref &&
            (sortop == InvalidOid ||
             sortop == scl->sortop ||
             sortop == get_commutator(scl->sortop)))
            return true;
    }
    return false;
}

References get_commutator(), InvalidOid, lfirst, TargetEntry::ressortgroupref, SortGroupClause::sortop, and SortGroupClause::tleSortGroupRef.

Referenced by addTargetToGroupList(), addTargetToSortList(), check_output_expressions(), examine_simple_variable(), targetIsInAllPartitionLists(), transformDistinctOnClause(), and transformGroupClauseExpr().

transformDistinctClause()

List * transformDistinctClause	(	ParseState *	pstate,
		List **	targetlist,
		List *	sortClause,
		bool	is_agg
	)

Definition at line 2985 of file parse_clause.c.

{
    List       *result = NIL;
    ListCell   *slitem;
    ListCell   *tlitem;
 
    /*
     * The distinctClause should consist of all ORDER BY items followed by all
     * other non-resjunk targetlist items.  There must not be any resjunk
     * ORDER BY items --- that would imply that we are sorting by a value that
     * isn't necessarily unique within a DISTINCT group, so the results
     * wouldn't be well-defined.  This construction ensures we follow the rule
     * that sortClause and distinctClause match; in fact the sortClause will
     * always be a prefix of distinctClause.
     *
     * Note a corner case: the same TLE could be in the ORDER BY list multiple
     * times with different sortops.  We have to include it in the
     * distinctClause the same way to preserve the prefix property. The net
     * effect will be that the TLE value will be made unique according to both
     * sortops.
     */
    foreach(slitem, sortClause)
    {
        SortGroupClause *scl = (SortGroupClause *) lfirst(slitem);
        TargetEntry *tle = get_sortgroupclause_tle(scl, *targetlist);
 
        if (tle->resjunk)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
                     is_agg ?
                     errmsg("in an aggregate with DISTINCT, ORDER BY expressions must appear in argument list") :
                     errmsg("for SELECT DISTINCT, ORDER BY expressions must appear in select list"),
                     parser_errposition(pstate,
                                        exprLocation((Node *) tle->expr))));
        result = lappend(result, copyObject(scl));
    }
 
    /*
     * Now add any remaining non-resjunk tlist items, using default sort/group
     * semantics for their data types.
     */
    foreach(tlitem, *targetlist)
    {
        TargetEntry *tle = (TargetEntry *) lfirst(tlitem);
 
        if (tle->resjunk)
            continue;           /* ignore junk */
        result = addTargetToGroupList(pstate, tle,
                                      result, *targetlist,
                                      exprLocation((Node *) tle->expr));
    }
 
    /*
     * Complain if we found nothing to make DISTINCT.  Returning an empty list
     * would cause the parsed Query to look like it didn't have DISTINCT, with
     * results that would probably surprise the user.  Note: this case is
     * presently impossible for aggregates because of grammar restrictions,
     * but we check anyway.
     */
    if (result == NIL)
        ereport(ERROR,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 is_agg ?
                 errmsg("an aggregate with DISTINCT must have at least one argument") :
                 errmsg("SELECT DISTINCT must have at least one column")));
 
    return result;
}

References addTargetToGroupList(), copyObject, ereport, errcode(), errmsg(), ERROR, TargetEntry::expr, exprLocation(), get_sortgroupclause_tle(), lappend(), lfirst, NIL, and parser_errposition().

Referenced by transformAggregateCall(), transformPLAssignStmt(), and transformSelectStmt().

transformDistinctOnClause()

List * transformDistinctOnClause	(	ParseState *	pstate,
		List *	distinctlist,
		List **	targetlist,
		List *	sortClause
	)

Definition at line 3069 of file parse_clause.c.

{
    List       *result = NIL;
    List       *sortgrouprefs = NIL;
    bool        skipped_sortitem;
    ListCell   *lc;
    ListCell   *lc2;
 
    /*
     * Add all the DISTINCT ON expressions to the tlist (if not already
     * present, they are added as resjunk items).  Assign sortgroupref numbers
     * to them, and make a list of these numbers.  (NB: we rely below on the
     * sortgrouprefs list being one-for-one with the original distinctlist.
     * Also notice that we could have duplicate DISTINCT ON expressions and
     * hence duplicate entries in sortgrouprefs.)
     */
    foreach(lc, distinctlist)
    {
        Node       *dexpr = (Node *) lfirst(lc);
        int         sortgroupref;
        TargetEntry *tle;
 
        tle = findTargetlistEntrySQL92(pstate, dexpr, targetlist,
                                       EXPR_KIND_DISTINCT_ON);
        sortgroupref = assignSortGroupRef(tle, *targetlist);
        sortgrouprefs = lappend_int(sortgrouprefs, sortgroupref);
    }
 
    /*
     * If the user writes both DISTINCT ON and ORDER BY, adopt the sorting
     * semantics from ORDER BY items that match DISTINCT ON items, and also
     * adopt their column sort order.  We insist that the distinctClause and
     * sortClause match, so throw error if we find the need to add any more
     * distinctClause items after we've skipped an ORDER BY item that wasn't
     * in DISTINCT ON.
     */
    skipped_sortitem = false;
    foreach(lc, sortClause)
    {
        SortGroupClause *scl = (SortGroupClause *) lfirst(lc);
 
        if (list_member_int(sortgrouprefs, scl->tleSortGroupRef))
        {
            if (skipped_sortitem)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
                         errmsg("SELECT DISTINCT ON expressions must match initial ORDER BY expressions"),
                         parser_errposition(pstate,
                                            get_matching_location(scl->tleSortGroupRef,
                                                                  sortgrouprefs,
                                                                  distinctlist))));
            else
                result = lappend(result, copyObject(scl));
        }
        else
            skipped_sortitem = true;
    }
 
    /*
     * Now add any remaining DISTINCT ON items, using default sort/group
     * semantics for their data types.  (Note: this is pretty questionable; if
     * the ORDER BY list doesn't include all the DISTINCT ON items and more
     * besides, you certainly aren't using DISTINCT ON in the intended way,
     * and you probably aren't going to get consistent results.  It might be
     * better to throw an error or warning here.  But historically we've
     * allowed it, so keep doing so.)
     */
    forboth(lc, distinctlist, lc2, sortgrouprefs)
    {
        Node       *dexpr = (Node *) lfirst(lc);
        int         sortgroupref = lfirst_int(lc2);
        TargetEntry *tle = get_sortgroupref_tle(sortgroupref, *targetlist);
 
        if (targetIsInSortList(tle, InvalidOid, result))
            continue;           /* already in list (with some semantics) */
        if (skipped_sortitem)
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
                     errmsg("SELECT DISTINCT ON expressions must match initial ORDER BY expressions"),
                     parser_errposition(pstate, exprLocation(dexpr))));
        result = addTargetToGroupList(pstate, tle,
                                      result, *targetlist,
                                      exprLocation(dexpr));
    }
 
    /*
     * An empty result list is impossible here because of grammar
     * restrictions.
     */
    Assert(result != NIL);
 
    return result;
}

References addTargetToGroupList(), Assert, assignSortGroupRef(), copyObject, ereport, errcode(), errmsg(), ERROR, EXPR_KIND_DISTINCT_ON, exprLocation(), findTargetlistEntrySQL92(), forboth, get_matching_location(), get_sortgroupref_tle(), InvalidOid, lappend(), lappend_int(), lfirst, lfirst_int, list_member_int(), NIL, parser_errposition(), targetIsInSortList(), and SortGroupClause::tleSortGroupRef.

Referenced by transformPLAssignStmt(), and transformSelectStmt().

transformFrameOffset()

static Node * transformFrameOffset ( ParseState *  pstate, int  frameOptions, Oid  rangeopfamily, Oid  rangeopcintype, Oid *  inRangeFunc, Node *  clause  )

static

Definition at line 3689 of file parse_clause.c.

{
    const char *constructName = NULL;
    Node       *node;
 
    *inRangeFunc = InvalidOid;  /* default result */
 
    /* Quick exit if no offset expression */
    if (clause == NULL)
        return NULL;
 
    if (frameOptions & FRAMEOPTION_ROWS)
    {
        /* Transform the raw expression tree */
        node = transformExpr(pstate, clause, EXPR_KIND_WINDOW_FRAME_ROWS);
 
        /*
         * Like LIMIT clause, simply coerce to int8
         */
        constructName = "ROWS";
        node = coerce_to_specific_type(pstate, node, INT8OID, constructName);
    }
    else if (frameOptions & FRAMEOPTION_RANGE)
    {
        /*
         * We must look up the in_range support function that's to be used,
         * possibly choosing one of several, and coerce the "offset" value to
         * the appropriate input type.
         */
        Oid         nodeType;
        Oid         preferredType;
        int         nfuncs = 0;
        int         nmatches = 0;
        Oid         selectedType = InvalidOid;
        Oid         selectedFunc = InvalidOid;
        CatCList   *proclist;
        int         i;
 
        /* Transform the raw expression tree */
        node = transformExpr(pstate, clause, EXPR_KIND_WINDOW_FRAME_RANGE);
        nodeType = exprType(node);
 
        /*
         * If there are multiple candidates, we'll prefer the one that exactly
         * matches nodeType; or if nodeType is as yet unknown, prefer the one
         * that exactly matches the sort column type.  (The second rule is
         * like what we do for "known_type operator unknown".)
         */
        preferredType = (nodeType != UNKNOWNOID) ? nodeType : rangeopcintype;
 
        /* Find the in_range support functions applicable to this case */
        proclist = SearchSysCacheList2(AMPROCNUM,
                                       ObjectIdGetDatum(rangeopfamily),
                                       ObjectIdGetDatum(rangeopcintype));
        for (i = 0; i < proclist->n_members; i++)
        {
            HeapTuple   proctup = &proclist->members[i]->tuple;
            Form_pg_amproc procform = (Form_pg_amproc) GETSTRUCT(proctup);
 
            /* The search will find all support proc types; ignore others */
            if (procform->amprocnum != BTINRANGE_PROC)
                continue;
            nfuncs++;
 
            /* Ignore function if given value can't be coerced to that type */
            if (!can_coerce_type(1, &nodeType, &procform->amprocrighttype,
                                 COERCION_IMPLICIT))
                continue;
            nmatches++;
 
            /* Remember preferred match, or any match if didn't find that */
            if (selectedType != preferredType)
            {
                selectedType = procform->amprocrighttype;
                selectedFunc = procform->amproc;
            }
        }
        ReleaseCatCacheList(proclist);
 
        /*
         * Throw error if needed.  It seems worth taking the trouble to
         * distinguish "no support at all" from "you didn't match any
         * available offset type".
         */
        if (nfuncs == 0)
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("RANGE with offset PRECEDING/FOLLOWING is not supported for column type %s",
                            format_type_be(rangeopcintype)),
                     parser_errposition(pstate, exprLocation(node))));
        if (nmatches == 0)
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("RANGE with offset PRECEDING/FOLLOWING is not supported for column type %s and offset type %s",
                            format_type_be(rangeopcintype),
                            format_type_be(nodeType)),
                     errhint("Cast the offset value to an appropriate type."),
                     parser_errposition(pstate, exprLocation(node))));
        if (nmatches != 1 && selectedType != preferredType)
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("RANGE with offset PRECEDING/FOLLOWING has multiple interpretations for column type %s and offset type %s",
                            format_type_be(rangeopcintype),
                            format_type_be(nodeType)),
                     errhint("Cast the offset value to the exact intended type."),
                     parser_errposition(pstate, exprLocation(node))));
 
        /* OK, coerce the offset to the right type */
        constructName = "RANGE";
        node = coerce_to_specific_type(pstate, node,
                                       selectedType, constructName);
        *inRangeFunc = selectedFunc;
    }
    else if (frameOptions & FRAMEOPTION_GROUPS)
    {
        /* Transform the raw expression tree */
        node = transformExpr(pstate, clause, EXPR_KIND_WINDOW_FRAME_GROUPS);
 
        /*
         * Like LIMIT clause, simply coerce to int8
         */
        constructName = "GROUPS";
        node = coerce_to_specific_type(pstate, node, INT8OID, constructName);
    }
    else
    {
        Assert(false);
        node = NULL;
    }
 
    /* Disallow variables in frame offsets */
    checkExprIsVarFree(pstate, node, constructName);
 
    return node;
}

References Assert, BTINRANGE_PROC, can_coerce_type(), checkExprIsVarFree(), coerce_to_specific_type(), COERCION_IMPLICIT, ereport, errcode(), errhint(), errmsg(), ERROR, EXPR_KIND_WINDOW_FRAME_GROUPS, EXPR_KIND_WINDOW_FRAME_RANGE, EXPR_KIND_WINDOW_FRAME_ROWS, exprLocation(), exprType(), format_type_be(), FRAMEOPTION_GROUPS, FRAMEOPTION_RANGE, FRAMEOPTION_ROWS, GETSTRUCT(), i, InvalidOid, catclist::members, catclist::n_members, ObjectIdGetDatum(), parser_errposition(), ReleaseCatCacheList(), SearchSysCacheList2, transformExpr(), and catctup::tuple.

Referenced by transformWindowDefinitions().

transformFromClause()

void transformFromClause	(	ParseState *	pstate,
		List *	frmList
	)

Definition at line 112 of file parse_clause.c.

{
    ListCell   *fl;
 
    /*
     * The grammar will have produced a list of RangeVars, RangeSubselects,
     * RangeFunctions, and/or JoinExprs. Transform each one (possibly adding
     * entries to the rtable), check for duplicate refnames, and then add it
     * to the joinlist and namespace.
     *
     * Note we must process the items left-to-right for proper handling of
     * LATERAL references.
     */
    foreach(fl, frmList)
    {
        Node       *n = lfirst(fl);
        ParseNamespaceItem *nsitem;
        List       *namespace;
 
        n = transformFromClauseItem(pstate, n,
                                    &nsitem,
                                    &namespace);
 
        checkNameSpaceConflicts(pstate, pstate->p_namespace, namespace);
 
        /* Mark the new namespace items as visible only to LATERAL */
        setNamespaceLateralState(namespace, true, true);
 
        pstate->p_joinlist = lappend(pstate->p_joinlist, n);
        pstate->p_namespace = list_concat(pstate->p_namespace, namespace);
    }
 
    /*
     * We're done parsing the FROM list, so make all namespace items
     * unconditionally visible.  Note that this will also reset lateral_only
     * for any namespace items that were already present when we were called;
     * but those should have been that way already.
     */
    setNamespaceLateralState(pstate->p_namespace, false, true);
}

References checkNameSpaceConflicts(), lappend(), lfirst, list_concat(), ParseState::p_joinlist, ParseState::p_namespace, setNamespaceLateralState(), and transformFromClauseItem().

Referenced by transformDeleteStmt(), transformMergeStmt(), transformPLAssignStmt(), transformSelectStmt(), and transformUpdateStmt().

transformFromClauseItem()

static Node * transformFromClauseItem ( ParseState *  pstate, Node *  n, ParseNamespaceItem **  top_nsitem, List **  namespace  )

static

Definition at line 1054 of file parse_clause.c.

{
    /* Guard against stack overflow due to overly deep subtree */
    check_stack_depth();
 
    if (IsA(n, RangeVar))
    {
        /* Plain relation reference, or perhaps a CTE reference */
        RangeVar   *rv = (RangeVar *) n;
        RangeTblRef *rtr;
        ParseNamespaceItem *nsitem;
 
        /* Check if it's a CTE or tuplestore reference */
        nsitem = getNSItemForSpecialRelationTypes(pstate, rv);
 
        /* if not found above, must be a table reference */
        if (!nsitem)
            nsitem = transformTableEntry(pstate, rv);
 
        *top_nsitem = nsitem;
        *namespace = list_make1(nsitem);
        rtr = makeNode(RangeTblRef);
        rtr->rtindex = nsitem->p_rtindex;
        return (Node *) rtr;
    }
    else if (IsA(n, RangeSubselect))
    {
        /* sub-SELECT is like a plain relation */
        RangeTblRef *rtr;
        ParseNamespaceItem *nsitem;
 
        nsitem = transformRangeSubselect(pstate, (RangeSubselect *) n);
        *top_nsitem = nsitem;
        *namespace = list_make1(nsitem);
        rtr = makeNode(RangeTblRef);
        rtr->rtindex = nsitem->p_rtindex;
        return (Node *) rtr;
    }
    else if (IsA(n, RangeFunction))
    {
        /* function is like a plain relation */
        RangeTblRef *rtr;
        ParseNamespaceItem *nsitem;
 
        nsitem = transformRangeFunction(pstate, (RangeFunction *) n);
        *top_nsitem = nsitem;
        *namespace = list_make1(nsitem);
        rtr = makeNode(RangeTblRef);
        rtr->rtindex = nsitem->p_rtindex;
        return (Node *) rtr;
    }
    else if (IsA(n, RangeTableFunc) || IsA(n, JsonTable))
    {
        /* table function is like a plain relation */
        RangeTblRef *rtr;
        ParseNamespaceItem *nsitem;
 
        if (IsA(n, JsonTable))
            nsitem = transformJsonTable(pstate, (JsonTable *) n);
        else
            nsitem = transformRangeTableFunc(pstate, (RangeTableFunc *) n);
 
        *top_nsitem = nsitem;
        *namespace = list_make1(nsitem);
        rtr = makeNode(RangeTblRef);
        rtr->rtindex = nsitem->p_rtindex;
        return (Node *) rtr;
    }
    else if (IsA(n, RangeTableSample))
    {
        /* TABLESAMPLE clause (wrapping some other valid FROM node) */
        RangeTableSample *rts = (RangeTableSample *) n;
        Node       *rel;
        RangeTblEntry *rte;
 
        /* Recursively transform the contained relation */
        rel = transformFromClauseItem(pstate, rts->relation,
                                      top_nsitem, namespace);
        rte = (*top_nsitem)->p_rte;
        /* We only support this on plain relations and matviews */
        if (rte->rtekind != RTE_RELATION ||
            (rte->relkind != RELKIND_RELATION &&
             rte->relkind != RELKIND_MATVIEW &&
             rte->relkind != RELKIND_PARTITIONED_TABLE))
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("TABLESAMPLE clause can only be applied to tables and materialized views"),
                     parser_errposition(pstate, exprLocation(rts->relation))));
 
        /* Transform TABLESAMPLE details and attach to the RTE */
        rte->tablesample = transformRangeTableSample(pstate, rts);
        return rel;
    }
    else if (IsA(n, JoinExpr))
    {
        /* A newfangled join expression */
        JoinExpr   *j = (JoinExpr *) n;
        ParseNamespaceItem *nsitem;
        ParseNamespaceItem *l_nsitem;
        ParseNamespaceItem *r_nsitem;
        List       *l_namespace,
                   *r_namespace,
                   *my_namespace,
                   *l_colnames,
                   *r_colnames,
                   *res_colnames,
                   *l_colnos,
                   *r_colnos,
                   *res_colvars;
        ParseNamespaceColumn *l_nscolumns,
                   *r_nscolumns,
                   *res_nscolumns;
        int         res_colindex;
        bool        lateral_ok;
        int         sv_namespace_length;
        int         k;
 
        /*
         * Recursively process the left subtree, then the right.  We must do
         * it in this order for correct visibility of LATERAL references.
         */
        j->larg = transformFromClauseItem(pstate, j->larg,
                                          &l_nsitem,
                                          &l_namespace);
 
        /*
         * Make the left-side RTEs available for LATERAL access within the
         * right side, by temporarily adding them to the pstate's namespace
         * list.  Per SQL:2008, if the join type is not INNER or LEFT then the
         * left-side names must still be exposed, but it's an error to
         * reference them.  (Stupid design, but that's what it says.)  Hence,
         * we always push them into the namespace, but mark them as not
         * lateral_ok if the jointype is wrong.
         *
         * Notice that we don't require the merged namespace list to be
         * conflict-free.  See the comments for scanNameSpaceForRefname().
         */
        lateral_ok = (j->jointype == JOIN_INNER || j->jointype == JOIN_LEFT);
        setNamespaceLateralState(l_namespace, true, lateral_ok);
 
        sv_namespace_length = list_length(pstate->p_namespace);
        pstate->p_namespace = list_concat(pstate->p_namespace, l_namespace);
 
        /* And now we can process the RHS */
        j->rarg = transformFromClauseItem(pstate, j->rarg,
                                          &r_nsitem,
                                          &r_namespace);
 
        /* Remove the left-side RTEs from the namespace list again */
        pstate->p_namespace = list_truncate(pstate->p_namespace,
                                            sv_namespace_length);
 
        /*
         * Check for conflicting refnames in left and right subtrees. Must do
         * this because higher levels will assume I hand back a self-
         * consistent namespace list.
         */
        checkNameSpaceConflicts(pstate, l_namespace, r_namespace);
 
        /*
         * Generate combined namespace info for possible use below.
         */
        my_namespace = list_concat(l_namespace, r_namespace);
 
        /*
         * We'll work from the nscolumns data and eref alias column names for
         * each of the input nsitems.  Note that these include dropped
         * columns, which is helpful because we can keep track of physical
         * input column numbers more easily.
         */
        l_nscolumns = l_nsitem->p_nscolumns;
        l_colnames = l_nsitem->p_names->colnames;
        r_nscolumns = r_nsitem->p_nscolumns;
        r_colnames = r_nsitem->p_names->colnames;
 
        /*
         * Natural join does not explicitly specify columns; must generate
         * columns to join. Need to run through the list of columns from each
         * table or join result and match up the column names. Use the first
         * table, and check every column in the second table for a match.
         * (We'll check that the matches were unique later on.) The result of
         * this step is a list of column names just like an explicitly-written
         * USING list.
         */
        if (j->isNatural)
        {
            List       *rlist = NIL;
            ListCell   *lx,
                       *rx;
 
            Assert(j->usingClause == NIL);  /* shouldn't have USING() too */
 
            foreach(lx, l_colnames)
            {
                char       *l_colname = strVal(lfirst(lx));
                String     *m_name = NULL;
 
                if (l_colname[0] == '\0')
                    continue;   /* ignore dropped columns */
 
                foreach(rx, r_colnames)
                {
                    char       *r_colname = strVal(lfirst(rx));
 
                    if (strcmp(l_colname, r_colname) == 0)
                    {
                        m_name = makeString(l_colname);
                        break;
                    }
                }
 
                /* matched a right column? then keep as join column... */
                if (m_name != NULL)
                    rlist = lappend(rlist, m_name);
            }
 
            j->usingClause = rlist;
        }
 
        /*
         * If a USING clause alias was specified, save the USING columns as
         * its column list.
         */
        if (j->join_using_alias)
            j->join_using_alias->colnames = j->usingClause;
 
        /*
         * Now transform the join qualifications, if any.
         */
        l_colnos = NIL;
        r_colnos = NIL;
        res_colnames = NIL;
        res_colvars = NIL;
 
        /* this may be larger than needed, but it's not worth being exact */
        res_nscolumns = (ParseNamespaceColumn *)
            palloc0((list_length(l_colnames) + list_length(r_colnames)) *
                    sizeof(ParseNamespaceColumn));
        res_colindex = 0;
 
        if (j->usingClause)
        {
            /*
             * JOIN/USING (or NATURAL JOIN, as transformed above). Transform
             * the list into an explicit ON-condition.
             */
            List       *ucols = j->usingClause;
            List       *l_usingvars = NIL;
            List       *r_usingvars = NIL;
            ListCell   *ucol;
 
            Assert(j->quals == NULL);   /* shouldn't have ON() too */
 
            foreach(ucol, ucols)
            {
                char       *u_colname = strVal(lfirst(ucol));
                ListCell   *col;
                int         ndx;
                int         l_index = -1;
                int         r_index = -1;
                Var        *l_colvar,
                           *r_colvar;
 
                Assert(u_colname[0] != '\0');
 
                /* Check for USING(foo,foo) */
                foreach(col, res_colnames)
                {
                    char       *res_colname = strVal(lfirst(col));
 
                    if (strcmp(res_colname, u_colname) == 0)
                        ereport(ERROR,
                                (errcode(ERRCODE_DUPLICATE_COLUMN),
                                 errmsg("column name \"%s\" appears more than once in USING clause",
                                        u_colname)));
                }
 
                /* Find it in left input */
                ndx = 0;
                foreach(col, l_colnames)
                {
                    char       *l_colname = strVal(lfirst(col));
 
                    if (strcmp(l_colname, u_colname) == 0)
                    {
                        if (l_index >= 0)
                            ereport(ERROR,
                                    (errcode(ERRCODE_AMBIGUOUS_COLUMN),
                                     errmsg("common column name \"%s\" appears more than once in left table",
                                            u_colname)));
                        l_index = ndx;
                    }
                    ndx++;
                }
                if (l_index < 0)
                    ereport(ERROR,
                            (errcode(ERRCODE_UNDEFINED_COLUMN),
                             errmsg("column \"%s\" specified in USING clause does not exist in left table",
                                    u_colname)));
                l_colnos = lappend_int(l_colnos, l_index + 1);
 
                /* Find it in right input */
                ndx = 0;
                foreach(col, r_colnames)
                {
                    char       *r_colname = strVal(lfirst(col));
 
                    if (strcmp(r_colname, u_colname) == 0)
                    {
                        if (r_index >= 0)
                            ereport(ERROR,
                                    (errcode(ERRCODE_AMBIGUOUS_COLUMN),
                                     errmsg("common column name \"%s\" appears more than once in right table",
                                            u_colname)));
                        r_index = ndx;
                    }
                    ndx++;
                }
                if (r_index < 0)
                    ereport(ERROR,
                            (errcode(ERRCODE_UNDEFINED_COLUMN),
                             errmsg("column \"%s\" specified in USING clause does not exist in right table",
                                    u_colname)));
                r_colnos = lappend_int(r_colnos, r_index + 1);
 
                /* Build Vars to use in the generated JOIN ON clause */
                l_colvar = buildVarFromNSColumn(pstate, l_nscolumns + l_index);
                l_usingvars = lappend(l_usingvars, l_colvar);
                r_colvar = buildVarFromNSColumn(pstate, r_nscolumns + r_index);
                r_usingvars = lappend(r_usingvars, r_colvar);
 
                /*
                 * While we're here, add column names to the res_colnames
                 * list.  It's a bit ugly to do this here while the
                 * corresponding res_colvars entries are not made till later,
                 * but doing this later would require an additional traversal
                 * of the usingClause list.
                 */
                res_colnames = lappend(res_colnames, lfirst(ucol));
            }
 
            /* Construct the generated JOIN ON clause */
            j->quals = transformJoinUsingClause(pstate,
                                                l_usingvars,
                                                r_usingvars);
        }
        else if (j->quals)
        {
            /* User-written ON-condition; transform it */
            j->quals = transformJoinOnClause(pstate, j, my_namespace);
        }
        else
        {
            /* CROSS JOIN: no quals */
        }
 
        /*
         * If this is an outer join, now mark the appropriate child RTEs as
         * being nulled by this join.  We have finished processing the child
         * join expressions as well as the current join's quals, which deal in
         * non-nulled input columns.  All future references to those RTEs will
         * see possibly-nulled values, and we should mark generated Vars to
         * account for that.  In particular, the join alias Vars that we're
         * about to build should reflect the nulling effects of this join.
         *
         * A difficulty with doing this is that we need the join's RT index,
         * which we don't officially have yet.  However, no other RTE can get
         * made between here and the addRangeTableEntryForJoin call, so we can
         * predict what the assignment will be.  (Alternatively, we could call
         * addRangeTableEntryForJoin before we have all the data computed, but
         * this seems less ugly.)
         */
        j->rtindex = list_length(pstate->p_rtable) + 1;
 
        switch (j->jointype)
        {
            case JOIN_INNER:
                break;
            case JOIN_LEFT:
                markRelsAsNulledBy(pstate, j->rarg, j->rtindex);
                break;
            case JOIN_FULL:
                markRelsAsNulledBy(pstate, j->larg, j->rtindex);
                markRelsAsNulledBy(pstate, j->rarg, j->rtindex);
                break;
            case JOIN_RIGHT:
                markRelsAsNulledBy(pstate, j->larg, j->rtindex);
                break;
            default:
                /* shouldn't see any other types here */
                elog(ERROR, "unrecognized join type: %d",
                     (int) j->jointype);
                break;
        }
 
        /*
         * Now we can construct join alias expressions for the USING columns.
         */
        if (j->usingClause)
        {
            ListCell   *lc1,
                       *lc2;
 
            /* Scan the colnos lists to recover info from the previous loop */
            forboth(lc1, l_colnos, lc2, r_colnos)
            {
                int         l_index = lfirst_int(lc1) - 1;
                int         r_index = lfirst_int(lc2) - 1;
                Var        *l_colvar,
                           *r_colvar;
                Node       *u_colvar;
                ParseNamespaceColumn *res_nscolumn;
 
                /*
                 * Note we re-build these Vars: they might have different
                 * varnullingrels than the ones made in the previous loop.
                 */
                l_colvar = buildVarFromNSColumn(pstate, l_nscolumns + l_index);
                r_colvar = buildVarFromNSColumn(pstate, r_nscolumns + r_index);
 
                /* Construct the join alias Var for this column */
                u_colvar = buildMergedJoinVar(pstate,
                                              j->jointype,
                                              l_colvar,
                                              r_colvar);
                res_colvars = lappend(res_colvars, u_colvar);
 
                /* Construct column's res_nscolumns[] entry */
                res_nscolumn = res_nscolumns + res_colindex;
                res_colindex++;
                if (u_colvar == (Node *) l_colvar)
                {
                    /* Merged column is equivalent to left input */
                    *res_nscolumn = l_nscolumns[l_index];
                }
                else if (u_colvar == (Node *) r_colvar)
                {
                    /* Merged column is equivalent to right input */
                    *res_nscolumn = r_nscolumns[r_index];
                }
                else
                {
                    /*
                     * Merged column is not semantically equivalent to either
                     * input, so it needs to be referenced as the join output
                     * column.
                     */
                    res_nscolumn->p_varno = j->rtindex;
                    res_nscolumn->p_varattno = res_colindex;
                    res_nscolumn->p_vartype = exprType(u_colvar);
                    res_nscolumn->p_vartypmod = exprTypmod(u_colvar);
                    res_nscolumn->p_varcollid = exprCollation(u_colvar);
                    res_nscolumn->p_varnosyn = j->rtindex;
                    res_nscolumn->p_varattnosyn = res_colindex;
                }
            }
        }
 
        /* Add remaining columns from each side to the output columns */
        res_colindex +=
            extractRemainingColumns(pstate,
                                    l_nscolumns, l_colnames, &l_colnos,
                                    &res_colnames, &res_colvars,
                                    res_nscolumns + res_colindex);
        res_colindex +=
            extractRemainingColumns(pstate,
                                    r_nscolumns, r_colnames, &r_colnos,
                                    &res_colnames, &res_colvars,
                                    res_nscolumns + res_colindex);
 
        /* If join has an alias, it syntactically hides all inputs */
        if (j->alias)
        {
            for (k = 0; k < res_colindex; k++)
            {
                ParseNamespaceColumn *nscol = res_nscolumns + k;
 
                nscol->p_varnosyn = j->rtindex;
                nscol->p_varattnosyn = k + 1;
            }
        }
 
        /*
         * Now build an RTE and nsitem for the result of the join.
         */
        nsitem = addRangeTableEntryForJoin(pstate,
                                           res_colnames,
                                           res_nscolumns,
                                           j->jointype,
                                           list_length(j->usingClause),
                                           res_colvars,
                                           l_colnos,
                                           r_colnos,
                                           j->join_using_alias,
                                           j->alias,
                                           true);
 
        /* Verify that we correctly predicted the join's RT index */
        Assert(j->rtindex == nsitem->p_rtindex);
        /* Cross-check number of columns, too */
        Assert(res_colindex == list_length(nsitem->p_names->colnames));
 
        /*
         * Save a link to the JoinExpr in the proper element of p_joinexprs.
         * Since we maintain that list lazily, it may be necessary to fill in
         * empty entries before we can add the JoinExpr in the right place.
         */
        for (k = list_length(pstate->p_joinexprs) + 1; k < j->rtindex; k++)
            pstate->p_joinexprs = lappend(pstate->p_joinexprs, NULL);
        pstate->p_joinexprs = lappend(pstate->p_joinexprs, j);
        Assert(list_length(pstate->p_joinexprs) == j->rtindex);
 
        /*
         * If the join has a USING alias, build a ParseNamespaceItem for that
         * and add it to the list of nsitems in the join's input.
         */
        if (j->join_using_alias)
        {
            ParseNamespaceItem *jnsitem;
 
            jnsitem = (ParseNamespaceItem *) palloc(sizeof(ParseNamespaceItem));
            jnsitem->p_names = j->join_using_alias;
            jnsitem->p_rte = nsitem->p_rte;
            jnsitem->p_rtindex = nsitem->p_rtindex;
            jnsitem->p_perminfo = NULL;
            /* no need to copy the first N columns, just use res_nscolumns */
            jnsitem->p_nscolumns = res_nscolumns;
            /* set default visibility flags; might get changed later */
            jnsitem->p_rel_visible = true;
            jnsitem->p_cols_visible = true;
            jnsitem->p_lateral_only = false;
            jnsitem->p_lateral_ok = true;
            jnsitem->p_returning_type = VAR_RETURNING_DEFAULT;
            /* Per SQL, we must check for alias conflicts */
            checkNameSpaceConflicts(pstate, list_make1(jnsitem), my_namespace);
            my_namespace = lappend(my_namespace, jnsitem);
        }
 
        /*
         * Prepare returned namespace list.  If the JOIN has an alias then it
         * hides the contained RTEs completely; otherwise, the contained RTEs
         * are still visible as table names, but are not visible for
         * unqualified column-name access.
         *
         * Note: if there are nested alias-less JOINs, the lower-level ones
         * will remain in the list although they have neither p_rel_visible
         * nor p_cols_visible set.  We could delete such list items, but it's
         * unclear that it's worth expending cycles to do so.
         */
        if (j->alias != NULL)
            my_namespace = NIL;
        else
            setNamespaceColumnVisibility(my_namespace, false);
 
        /*
         * The join RTE itself is always made visible for unqualified column
         * names.  It's visible as a relation name only if it has an alias.
         */
        nsitem->p_rel_visible = (j->alias != NULL);
        nsitem->p_cols_visible = true;
        nsitem->p_lateral_only = false;
        nsitem->p_lateral_ok = true;
 
        *top_nsitem = nsitem;
        *namespace = lappend(my_namespace, nsitem);
 
        return (Node *) j;
    }
    else
        elog(ERROR, "unrecognized node type: %d", (int) nodeTag(n));
    return NULL;                /* can't get here, keep compiler quiet */
}

References addRangeTableEntryForJoin(), Assert, buildMergedJoinVar(), buildVarFromNSColumn(), check_stack_depth(), checkNameSpaceConflicts(), Alias::colnames, elog, ereport, errcode(), errmsg(), ERROR, exprCollation(), exprLocation(), exprType(), exprTypmod(), extractRemainingColumns(), forboth, getNSItemForSpecialRelationTypes(), IsA, j, JOIN_FULL, JOIN_INNER, JOIN_LEFT, JOIN_RIGHT, lappend(), lappend_int(), lfirst, lfirst_int, list_concat(), list_length(), list_make1, list_truncate(), makeNode, makeString(), markRelsAsNulledBy(), NIL, nodeTag, ParseNamespaceItem::p_cols_visible, ParseState::p_joinexprs, ParseNamespaceItem::p_lateral_ok, ParseNamespaceItem::p_lateral_only, ParseNamespaceItem::p_names, ParseState::p_namespace, ParseNamespaceItem::p_nscolumns, ParseNamespaceItem::p_perminfo, ParseNamespaceItem::p_rel_visible, ParseNamespaceItem::p_returning_type, ParseState::p_rtable, ParseNamespaceItem::p_rte, ParseNamespaceItem::p_rtindex, ParseNamespaceColumn::p_varattno, ParseNamespaceColumn::p_varattnosyn, ParseNamespaceColumn::p_varcollid, ParseNamespaceColumn::p_varno, ParseNamespaceColumn::p_varnosyn, ParseNamespaceColumn::p_vartype, ParseNamespaceColumn::p_vartypmod, palloc(), palloc0(), parser_errposition(), RangeTableSample::relation, RTE_RELATION, RangeTblEntry::rtekind, RangeTblRef::rtindex, setNamespaceColumnVisibility(), setNamespaceLateralState(), strVal, RangeTblEntry::tablesample, transformFromClauseItem(), transformJoinOnClause(), transformJoinUsingClause(), transformJsonTable(), transformRangeFunction(), transformRangeSubselect(), transformRangeTableFunc(), transformRangeTableSample(), transformTableEntry(), and VAR_RETURNING_DEFAULT.

Referenced by transformFromClause(), and transformFromClauseItem().

transformGroupClause()

List * transformGroupClause	(	ParseState *	pstate,
		List *	grouplist,
		List **	groupingSets,
		List **	targetlist,
		List *	sortClause,
		ParseExprKind	exprKind,
		bool	useSQL99
	)

Definition at line 2632 of file parse_clause.c.

{
    List       *result = NIL;
    List       *flat_grouplist;
    List       *gsets = NIL;
    ListCell   *gl;
    bool        hasGroupingSets = false;
    Bitmapset  *seen_local = NULL;
 
    /*
     * Recursively flatten implicit RowExprs. (Technically this is only needed
     * for GROUP BY, per the syntax rules for grouping sets, but we do it
     * anyway.)
     */
    flat_grouplist = (List *) flatten_grouping_sets((Node *) grouplist,
                                                    true,
                                                    &hasGroupingSets);
 
    /*
     * If the list is now empty, but hasGroupingSets is true, it's because we
     * elided redundant empty grouping sets. Restore a single empty grouping
     * set to leave a canonical form: GROUP BY ()
     */
 
    if (flat_grouplist == NIL && hasGroupingSets)
    {
        flat_grouplist = list_make1(makeGroupingSet(GROUPING_SET_EMPTY,
                                                    NIL,
                                                    exprLocation((Node *) grouplist)));
    }
 
    foreach(gl, flat_grouplist)
    {
        Node       *gexpr = (Node *) lfirst(gl);
 
        if (IsA(gexpr, GroupingSet))
        {
            GroupingSet *gset = (GroupingSet *) gexpr;
 
            switch (gset->kind)
            {
                case GROUPING_SET_EMPTY:
                    gsets = lappend(gsets, gset);
                    break;
                case GROUPING_SET_SIMPLE:
                    /* can't happen */
                    Assert(false);
                    break;
                case GROUPING_SET_SETS:
                case GROUPING_SET_CUBE:
                case GROUPING_SET_ROLLUP:
                    gsets = lappend(gsets,
                                    transformGroupingSet(&result,
                                                         pstate, gset,
                                                         targetlist, sortClause,
                                                         exprKind, useSQL99, true));
                    break;
            }
        }
        else
        {
            Index       ref = transformGroupClauseExpr(&result, seen_local,
                                                       pstate, gexpr,
                                                       targetlist, sortClause,
                                                       exprKind, useSQL99, true);
 
            if (ref > 0)
            {
                seen_local = bms_add_member(seen_local, ref);
                if (hasGroupingSets)
                    gsets = lappend(gsets,
                                    makeGroupingSet(GROUPING_SET_SIMPLE,
                                                    list_make1_int(ref),
                                                    exprLocation(gexpr)));
            }
        }
    }
 
    /* parser should prevent this */
    Assert(gsets == NIL || groupingSets != NULL);
 
    if (groupingSets)
        *groupingSets = gsets;
 
    return result;
}

References Assert, bms_add_member(), exprLocation(), flatten_grouping_sets(), GROUPING_SET_CUBE, GROUPING_SET_EMPTY, GROUPING_SET_ROLLUP, GROUPING_SET_SETS, GROUPING_SET_SIMPLE, IsA, lappend(), lfirst, list_make1, list_make1_int, makeGroupingSet(), NIL, transformGroupClauseExpr(), and transformGroupingSet().

Referenced by transformPLAssignStmt(), transformSelectStmt(), and transformWindowDefinitions().

transformGroupClauseExpr()

static Index transformGroupClauseExpr ( List **  flatresult, Bitmapset *  seen_local, ParseState *  pstate, Node *  gexpr, List **  targetlist, List *  sortClause, ParseExprKind  exprKind, bool  useSQL99, bool  toplevel  )

static

Definition at line 2367 of file parse_clause.c.

{
    TargetEntry *tle;
    bool        found = false;
 
    if (useSQL99)
        tle = findTargetlistEntrySQL99(pstate, gexpr,
                                       targetlist, exprKind);
    else
        tle = findTargetlistEntrySQL92(pstate, gexpr,
                                       targetlist, exprKind);
 
    if (tle->ressortgroupref > 0)
    {
        ListCell   *sl;
 
        /*
         * Eliminate duplicates (GROUP BY x, x) but only at local level.
         * (Duplicates in grouping sets can affect the number of returned
         * rows, so can't be dropped indiscriminately.)
         *
         * Since we don't care about anything except the sortgroupref, we can
         * use a bitmapset rather than scanning lists.
         */
        if (bms_is_member(tle->ressortgroupref, seen_local))
            return 0;
 
        /*
         * If we're already in the flat clause list, we don't need to consider
         * adding ourselves again.
         */
        found = targetIsInSortList(tle, InvalidOid, *flatresult);
        if (found)
            return tle->ressortgroupref;
 
        /*
         * If the GROUP BY tlist entry also appears in ORDER BY, copy operator
         * info from the (first) matching ORDER BY item.  This means that if
         * you write something like "GROUP BY foo ORDER BY foo USING <<<", the
         * GROUP BY operation silently takes on the equality semantics implied
         * by the ORDER BY.  There are two reasons to do this: it improves the
         * odds that we can implement both GROUP BY and ORDER BY with a single
         * sort step, and it allows the user to choose the equality semantics
         * used by GROUP BY, should she be working with a datatype that has
         * more than one equality operator.
         *
         * If we're in a grouping set, though, we force our requested ordering
         * to be NULLS LAST, because if we have any hope of using a sorted agg
         * for the job, we're going to be tacking on generated NULL values
         * after the corresponding groups. If the user demands nulls first,
         * another sort step is going to be inevitable, but that's the
         * planner's problem.
         */
 
        foreach(sl, sortClause)
        {
            SortGroupClause *sc = (SortGroupClause *) lfirst(sl);
 
            if (sc->tleSortGroupRef == tle->ressortgroupref)
            {
                SortGroupClause *grpc = copyObject(sc);
 
                if (!toplevel)
                    grpc->nulls_first = false;
                *flatresult = lappend(*flatresult, grpc);
                found = true;
                break;
            }
        }
    }
 
    /*
     * If no match in ORDER BY, just add it to the result using default
     * sort/group semantics.
     */
    if (!found)
        *flatresult = addTargetToGroupList(pstate, tle,
                                           *flatresult, *targetlist,
                                           exprLocation(gexpr));
 
    /*
     * _something_ must have assigned us a sortgroupref by now...
     */
 
    return tle->ressortgroupref;
}

References addTargetToGroupList(), bms_is_member(), copyObject, exprLocation(), findTargetlistEntrySQL92(), findTargetlistEntrySQL99(), InvalidOid, lappend(), lfirst, SortGroupClause::nulls_first, TargetEntry::ressortgroupref, targetIsInSortList(), and SortGroupClause::tleSortGroupRef.

Referenced by transformGroupClause(), transformGroupClauseList(), and transformGroupingSet().

transformGroupClauseList()

static List * transformGroupClauseList ( List **  flatresult, ParseState *  pstate, List *  list, List **  targetlist, List *  sortClause, ParseExprKind  exprKind, bool  useSQL99, bool  toplevel  )

static

Definition at line 2475 of file parse_clause.c.

{
    Bitmapset  *seen_local = NULL;
    List       *result = NIL;
    ListCell   *gl;
 
    foreach(gl, list)
    {
        Node       *gexpr = (Node *) lfirst(gl);
 
        Index       ref = transformGroupClauseExpr(flatresult,
                                                   seen_local,
                                                   pstate,
                                                   gexpr,
                                                   targetlist,
                                                   sortClause,
                                                   exprKind,
                                                   useSQL99,
                                                   toplevel);
 
        if (ref > 0)
        {
            seen_local = bms_add_member(seen_local, ref);
            result = lappend_int(result, ref);
        }
    }
 
    return result;
}

References bms_add_member(), lappend_int(), lfirst, sort-test::list, NIL, and transformGroupClauseExpr().

Referenced by transformGroupingSet().

transformGroupingSet()

static Node * transformGroupingSet ( List **  flatresult, ParseState *  pstate, GroupingSet *  gset, List **  targetlist, List *  sortClause, ParseExprKind  exprKind, bool  useSQL99, bool  toplevel  )

static

Definition at line 2528 of file parse_clause.c.

{
    ListCell   *gl;
    List       *content = NIL;
 
    Assert(toplevel || gset->kind != GROUPING_SET_SETS);
 
    foreach(gl, gset->content)
    {
        Node       *n = lfirst(gl);
 
        if (IsA(n, List))
        {
            List       *l = transformGroupClauseList(flatresult,
                                                     pstate, (List *) n,
                                                     targetlist, sortClause,
                                                     exprKind, useSQL99, false);
 
            content = lappend(content, makeGroupingSet(GROUPING_SET_SIMPLE,
                                                       l,
                                                       exprLocation(n)));
        }
        else if (IsA(n, GroupingSet))
        {
            GroupingSet *gset2 = (GroupingSet *) lfirst(gl);
 
            content = lappend(content, transformGroupingSet(flatresult,
                                                            pstate, gset2,
                                                            targetlist, sortClause,
                                                            exprKind, useSQL99, false));
        }
        else
        {
            Index       ref = transformGroupClauseExpr(flatresult,
                                                       NULL,
                                                       pstate,
                                                       n,
                                                       targetlist,
                                                       sortClause,
                                                       exprKind,
                                                       useSQL99,
                                                       false);
 
            content = lappend(content, makeGroupingSet(GROUPING_SET_SIMPLE,
                                                       list_make1_int(ref),
                                                       exprLocation(n)));
        }
    }
 
    /* Arbitrarily cap the size of CUBE, which has exponential growth */
    if (gset->kind == GROUPING_SET_CUBE)
    {
        if (list_length(content) > 12)
            ereport(ERROR,
                    (errcode(ERRCODE_TOO_MANY_COLUMNS),
                     errmsg("CUBE is limited to 12 elements"),
                     parser_errposition(pstate, gset->location)));
    }
 
    return (Node *) makeGroupingSet(gset->kind, content, gset->location);
}

References Assert, GroupingSet::content, ereport, errcode(), errmsg(), ERROR, exprLocation(), GROUPING_SET_CUBE, GROUPING_SET_SETS, GROUPING_SET_SIMPLE, IsA, lappend(), lfirst, list_length(), list_make1_int, GroupingSet::location, makeGroupingSet(), NIL, parser_errposition(), transformGroupClauseExpr(), transformGroupClauseList(), and transformGroupingSet().

Referenced by transformGroupClause(), and transformGroupingSet().

transformJoinOnClause()

static Node * transformJoinOnClause ( ParseState *  pstate, JoinExpr *  j, List *  namespace  )

static

Definition at line 365 of file parse_clause.c.

{
    Node       *result;
    List       *save_namespace;
 
    /*
     * The namespace that the join expression should see is just the two
     * subtrees of the JOIN plus any outer references from upper pstate
     * levels.  Temporarily set this pstate's namespace accordingly.  (We need
     * not check for refname conflicts, because transformFromClauseItem()
     * already did.)  All namespace items are marked visible regardless of
     * LATERAL state.
     */
    setNamespaceLateralState(namespace, false, true);
 
    save_namespace = pstate->p_namespace;
    pstate->p_namespace = namespace;
 
    result = transformWhereClause(pstate, j->quals,
                                  EXPR_KIND_JOIN_ON, "JOIN/ON");
 
    pstate->p_namespace = save_namespace;
 
    return result;
}

References EXPR_KIND_JOIN_ON, j, ParseState::p_namespace, setNamespaceLateralState(), and transformWhereClause().

Referenced by transformFromClauseItem().

transformJoinUsingClause()

static Node * transformJoinUsingClause ( ParseState *  pstate, List *  leftVars, List *  rightVars  )

static

Definition at line 306 of file parse_clause.c.

{
    Node       *result;
    List       *andargs = NIL;
    ListCell   *lvars,
               *rvars;
 
    /*
     * We cheat a little bit here by building an untransformed operator tree
     * whose leaves are the already-transformed Vars.  This requires collusion
     * from transformExpr(), which normally could be expected to complain
     * about already-transformed subnodes.  However, this does mean that we
     * have to mark the columns as requiring SELECT privilege for ourselves;
     * transformExpr() won't do it.
     */
    forboth(lvars, leftVars, rvars, rightVars)
    {
        Var        *lvar = (Var *) lfirst(lvars);
        Var        *rvar = (Var *) lfirst(rvars);
        A_Expr     *e;
 
        /* Require read access to the join variables */
        markVarForSelectPriv(pstate, lvar);
        markVarForSelectPriv(pstate, rvar);
 
        /* Now create the lvar = rvar join condition */
        e = makeSimpleA_Expr(AEXPR_OP, "=",
                             (Node *) copyObject(lvar), (Node *) copyObject(rvar),
                             -1);
 
        /* Prepare to combine into an AND clause, if multiple join columns */
        andargs = lappend(andargs, e);
    }
 
    /* Only need an AND if there's more than one join column */
    if (list_length(andargs) == 1)
        result = (Node *) linitial(andargs);
    else
        result = (Node *) makeBoolExpr(AND_EXPR, andargs, -1);
 
    /*
     * Since the references are already Vars, and are certainly from the input
     * relations, we don't have to go through the same pushups that
     * transformJoinOnClause() does.  Just invoke transformExpr() to fix up
     * the operators, and we're done.
     */
    result = transformExpr(pstate, result, EXPR_KIND_JOIN_USING);
 
    result = coerce_to_boolean(pstate, result, "JOIN/USING");
 
    return result;
}

References AEXPR_OP, AND_EXPR, coerce_to_boolean(), copyObject, EXPR_KIND_JOIN_USING, forboth, lappend(), lfirst, linitial, list_length(), makeBoolExpr(), makeSimpleA_Expr(), markVarForSelectPriv(), NIL, and transformExpr().

Referenced by transformFromClauseItem().

transformLimitClause()

Node * transformLimitClause	(	ParseState *	pstate,
		Node *	clause,
		ParseExprKind	exprKind,
		const char *	constructName,
		LimitOption	limitOption
	)

Definition at line 1881 of file parse_clause.c.

{
    Node       *qual;
 
    if (clause == NULL)
        return NULL;
 
    qual = transformExpr(pstate, clause, exprKind);
 
    qual = coerce_to_specific_type(pstate, qual, INT8OID, constructName);
 
    /* LIMIT can't refer to any variables of the current query */
    checkExprIsVarFree(pstate, qual, constructName);
 
    /*
     * Don't allow NULLs in FETCH FIRST .. WITH TIES.  This test is ugly and
     * extremely simplistic, in that you can pass a NULL anyway by hiding it
     * inside an expression -- but this protects ruleutils against emitting an
     * unadorned NULL that's not accepted back by the grammar.
     */
    if (exprKind == EXPR_KIND_LIMIT && limitOption == LIMIT_OPTION_WITH_TIES &&
        IsA(clause, A_Const) && castNode(A_Const, clause)->isnull)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_ROW_COUNT_IN_LIMIT_CLAUSE),
                 errmsg("row count cannot be null in FETCH FIRST ... WITH TIES clause")));
 
    return qual;
}

References castNode, checkExprIsVarFree(), coerce_to_specific_type(), ereport, errcode(), errmsg(), ERROR, EXPR_KIND_LIMIT, IsA, LIMIT_OPTION_WITH_TIES, and transformExpr().

Referenced by transformPLAssignStmt(), transformSelectStmt(), transformSetOperationStmt(), and transformValuesClause().

transformOnConflictArbiter()

void transformOnConflictArbiter	(	ParseState *	pstate,
		OnConflictClause *	onConflictClause,
		List **	arbiterExpr,
		Node **	arbiterWhere,
		Oid *	constraint
	)

Definition at line 3297 of file parse_clause.c.

{
    InferClause *infer = onConflictClause->infer;
 
    *arbiterExpr = NIL;
    *arbiterWhere = NULL;
    *constraint = InvalidOid;
 
    if (onConflictClause->action == ONCONFLICT_UPDATE && !infer)
        ereport(ERROR,
                (errcode(ERRCODE_SYNTAX_ERROR),
                 errmsg("ON CONFLICT DO UPDATE requires inference specification or constraint name"),
                 errhint("For example, ON CONFLICT (column_name)."),
                 parser_errposition(pstate,
                                    exprLocation((Node *) onConflictClause))));
 
    /*
     * To simplify certain aspects of its design, speculative insertion into
     * system catalogs is disallowed
     */
    if (IsCatalogRelation(pstate->p_target_relation))
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("ON CONFLICT is not supported with system catalog tables"),
                 parser_errposition(pstate,
                                    exprLocation((Node *) onConflictClause))));
 
    /* Same applies to table used by logical decoding as catalog table */
    if (RelationIsUsedAsCatalogTable(pstate->p_target_relation))
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("ON CONFLICT is not supported on table \"%s\" used as a catalog table",
                        RelationGetRelationName(pstate->p_target_relation)),
                 parser_errposition(pstate,
                                    exprLocation((Node *) onConflictClause))));
 
    /* ON CONFLICT DO NOTHING does not require an inference clause */
    if (infer)
    {
        if (infer->indexElems)
            *arbiterExpr = resolve_unique_index_expr(pstate, infer,
                                                     pstate->p_target_relation);
 
        /*
         * Handling inference WHERE clause (for partial unique index
         * inference)
         */
        if (infer->whereClause)
            *arbiterWhere = transformExpr(pstate, infer->whereClause,
                                          EXPR_KIND_INDEX_PREDICATE);
 
        /*
         * If the arbiter is specified by constraint name, get the constraint
         * OID and mark the constrained columns as requiring SELECT privilege,
         * in the same way as would have happened if the arbiter had been
         * specified by explicit reference to the constraint's index columns.
         */
        if (infer->conname)
        {
            Oid         relid = RelationGetRelid(pstate->p_target_relation);
            RTEPermissionInfo *perminfo = pstate->p_target_nsitem->p_perminfo;
            Bitmapset  *conattnos;
 
            conattnos = get_relation_constraint_attnos(relid, infer->conname,
                                                       false, constraint);
 
            /* Make sure the rel as a whole is marked for SELECT access */
            perminfo->requiredPerms |= ACL_SELECT;
            /* Mark the constrained columns as requiring SELECT access */
            perminfo->selectedCols = bms_add_members(perminfo->selectedCols,
                                                     conattnos);
        }
    }
 
    /*
     * It's convenient to form a list of expressions based on the
     * representation used by CREATE INDEX, since the same restrictions are
     * appropriate (e.g. on subqueries).  However, from here on, a dedicated
     * primnode representation is used for inference elements, and so
     * assign_query_collations() can be trusted to do the right thing with the
     * post parse analysis query tree inference clause representation.
     */
}

References ACL_SELECT, OnConflictClause::action, bms_add_members(), InferClause::conname, ereport, errcode(), errhint(), errmsg(), ERROR, EXPR_KIND_INDEX_PREDICATE, exprLocation(), get_relation_constraint_attnos(), InferClause::indexElems, OnConflictClause::infer, InvalidOid, IsCatalogRelation(), NIL, ONCONFLICT_UPDATE, ParseNamespaceItem::p_perminfo, ParseState::p_target_nsitem, ParseState::p_target_relation, parser_errposition(), RelationGetRelationName, RelationGetRelid, RelationIsUsedAsCatalogTable, RTEPermissionInfo::requiredPerms, resolve_unique_index_expr(), RTEPermissionInfo::selectedCols, transformExpr(), and InferClause::whereClause.

Referenced by transformOnConflictClause().

transformRangeFunction()

static ParseNamespaceItem * transformRangeFunction ( ParseState *  pstate, RangeFunction *  r  )

static

Definition at line 463 of file parse_clause.c.

{
    List       *funcexprs = NIL;
    List       *funcnames = NIL;
    List       *coldeflists = NIL;
    bool        is_lateral;
    ListCell   *lc;
 
    /*
     * We make lateral_only names of this level visible, whether or not the
     * RangeFunction is explicitly marked LATERAL.  This is needed for SQL
     * spec compliance in the case of UNNEST(), and seems useful on
     * convenience grounds for all functions in FROM.
     *
     * (LATERAL can't nest within a single pstate level, so we don't need
     * save/restore logic here.)
     */
    Assert(!pstate->p_lateral_active);
    pstate->p_lateral_active = true;
 
    /*
     * Transform the raw expressions.
     *
     * While transforming, also save function names for possible use as alias
     * and column names.  We use the same transformation rules as for a SELECT
     * output expression.  For a FuncCall node, the result will be the
     * function name, but it is possible for the grammar to hand back other
     * node types.
     *
     * We have to get this info now, because FigureColname only works on raw
     * parsetrees.  Actually deciding what to do with the names is left up to
     * addRangeTableEntryForFunction.
     *
     * Likewise, collect column definition lists if there were any.  But
     * complain if we find one here and the RangeFunction has one too.
     */
    foreach(lc, r->functions)
    {
        List       *pair = (List *) lfirst(lc);
        Node       *fexpr;
        List       *coldeflist;
        Node       *newfexpr;
        Node       *last_srf;
 
        /* Disassemble the function-call/column-def-list pairs */
        Assert(list_length(pair) == 2);
        fexpr = (Node *) linitial(pair);
        coldeflist = (List *) lsecond(pair);
 
        /*
         * If we find a function call unnest() with more than one argument and
         * no special decoration, transform it into separate unnest() calls on
         * each argument.  This is a kluge, for sure, but it's less nasty than
         * other ways of implementing the SQL-standard UNNEST() syntax.
         *
         * If there is any decoration (including a coldeflist), we don't
         * transform, which probably means a no-such-function error later.  We
         * could alternatively throw an error right now, but that doesn't seem
         * tremendously helpful.  If someone is using any such decoration,
         * then they're not using the SQL-standard syntax, and they're more
         * likely expecting an un-tweaked function call.
         *
         * Note: the transformation changes a non-schema-qualified unnest()
         * function name into schema-qualified pg_catalog.unnest().  This
         * choice is also a bit debatable, but it seems reasonable to force
         * use of built-in unnest() when we make this transformation.
         */
        if (IsA(fexpr, FuncCall))
        {
            FuncCall   *fc = (FuncCall *) fexpr;
 
            if (list_length(fc->funcname) == 1 &&
                strcmp(strVal(linitial(fc->funcname)), "unnest") == 0 &&
                list_length(fc->args) > 1 &&
                fc->agg_order == NIL &&
                fc->agg_filter == NULL &&
                fc->over == NULL &&
                !fc->agg_star &&
                !fc->agg_distinct &&
                !fc->func_variadic &&
                coldeflist == NIL)
            {
                ListCell   *lc2;
 
                foreach(lc2, fc->args)
                {
                    Node       *arg = (Node *) lfirst(lc2);
                    FuncCall   *newfc;
 
                    last_srf = pstate->p_last_srf;
 
                    newfc = makeFuncCall(SystemFuncName("unnest"),
                                         list_make1(arg),
                                         COERCE_EXPLICIT_CALL,
                                         fc->location);
 
                    newfexpr = transformExpr(pstate, (Node *) newfc,
                                             EXPR_KIND_FROM_FUNCTION);
 
                    /* nodeFunctionscan.c requires SRFs to be at top level */
                    if (pstate->p_last_srf != last_srf &&
                        pstate->p_last_srf != newfexpr)
                        ereport(ERROR,
                                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                                 errmsg("set-returning functions must appear at top level of FROM"),
                                 parser_errposition(pstate,
                                                    exprLocation(pstate->p_last_srf))));
 
                    funcexprs = lappend(funcexprs, newfexpr);
 
                    funcnames = lappend(funcnames,
                                        FigureColname((Node *) newfc));
 
                    /* coldeflist is empty, so no error is possible */
 
                    coldeflists = lappend(coldeflists, coldeflist);
                }
                continue;       /* done with this function item */
            }
        }
 
        /* normal case ... */
        last_srf = pstate->p_last_srf;
 
        newfexpr = transformExpr(pstate, fexpr,
                                 EXPR_KIND_FROM_FUNCTION);
 
        /* nodeFunctionscan.c requires SRFs to be at top level */
        if (pstate->p_last_srf != last_srf &&
            pstate->p_last_srf != newfexpr)
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("set-returning functions must appear at top level of FROM"),
                     parser_errposition(pstate,
                                        exprLocation(pstate->p_last_srf))));
 
        funcexprs = lappend(funcexprs, newfexpr);
 
        funcnames = lappend(funcnames,
                            FigureColname(fexpr));
 
        if (coldeflist && r->coldeflist)
            ereport(ERROR,
                    (errcode(ERRCODE_SYNTAX_ERROR),
                     errmsg("multiple column definition lists are not allowed for the same function"),
                     parser_errposition(pstate,
                                        exprLocation((Node *) r->coldeflist))));
 
        coldeflists = lappend(coldeflists, coldeflist);
    }
 
    pstate->p_lateral_active = false;
 
    /*
     * We must assign collations now so that the RTE exposes correct collation
     * info for Vars created from it.
     */
    assign_list_collations(pstate, funcexprs);
 
    /*
     * Install the top-level coldeflist if there was one (we already checked
     * that there was no conflicting per-function coldeflist).
     *
     * We only allow this when there's a single function (even after UNNEST
     * expansion) and no WITH ORDINALITY.  The reason for the latter
     * restriction is that it's not real clear whether the ordinality column
     * should be in the coldeflist, and users are too likely to make mistakes
     * in one direction or the other.  Putting the coldeflist inside ROWS
     * FROM() is much clearer in this case.
     */
    if (r->coldeflist)
    {
        if (list_length(funcexprs) != 1)
        {
            if (r->is_rowsfrom)
                ereport(ERROR,
                        (errcode(ERRCODE_SYNTAX_ERROR),
                         errmsg("ROWS FROM() with multiple functions cannot have a column definition list"),
                         errhint("Put a separate column definition list for each function inside ROWS FROM()."),
                         parser_errposition(pstate,
                                            exprLocation((Node *) r->coldeflist))));
            else
                ereport(ERROR,
                        (errcode(ERRCODE_SYNTAX_ERROR),
                         errmsg("UNNEST() with multiple arguments cannot have a column definition list"),
                         errhint("Use separate UNNEST() calls inside ROWS FROM(), and attach a column definition list to each one."),
                         parser_errposition(pstate,
                                            exprLocation((Node *) r->coldeflist))));
        }
        if (r->ordinality)
            ereport(ERROR,
                    (errcode(ERRCODE_SYNTAX_ERROR),
                     errmsg("WITH ORDINALITY cannot be used with a column definition list"),
                     errhint("Put the column definition list inside ROWS FROM()."),
                     parser_errposition(pstate,
                                        exprLocation((Node *) r->coldeflist))));
 
        coldeflists = list_make1(r->coldeflist);
    }
 
    /*
     * Mark the RTE as LATERAL if the user said LATERAL explicitly, or if
     * there are any lateral cross-references in it.
     */
    is_lateral = r->lateral || contain_vars_of_level((Node *) funcexprs, 0);
 
    /*
     * OK, build an RTE and nsitem for the function.
     */
    return addRangeTableEntryForFunction(pstate,
                                         funcnames, funcexprs, coldeflists,
                                         r, is_lateral, true);
}

References addRangeTableEntryForFunction(), arg, Assert, assign_list_collations(), COERCE_EXPLICIT_CALL, RangeFunction::coldeflist, contain_vars_of_level(), ereport, errcode(), errhint(), errmsg(), ERROR, EXPR_KIND_FROM_FUNCTION, exprLocation(), fc(), FigureColname(), RangeFunction::functions, RangeFunction::is_rowsfrom, IsA, lappend(), RangeFunction::lateral, lfirst, linitial, list_length(), list_make1, lsecond, makeFuncCall(), NIL, RangeFunction::ordinality, ParseState::p_last_srf, ParseState::p_lateral_active, parser_errposition(), strVal, SystemFuncName(), and transformExpr().

Referenced by transformFromClauseItem().

transformRangeSubselect()

static ParseNamespaceItem * transformRangeSubselect ( ParseState *  pstate, RangeSubselect *  r  )

static

Definition at line 405 of file parse_clause.c.

{
    Query      *query;
 
    /*
     * Set p_expr_kind to show this parse level is recursing to a subselect.
     * We can't be nested within any expression, so don't need save-restore
     * logic here.
     */
    Assert(pstate->p_expr_kind == EXPR_KIND_NONE);
    pstate->p_expr_kind = EXPR_KIND_FROM_SUBSELECT;
 
    /*
     * If the subselect is LATERAL, make lateral_only names of this level
     * visible to it.  (LATERAL can't nest within a single pstate level, so we
     * don't need save/restore logic here.)
     */
    Assert(!pstate->p_lateral_active);
    pstate->p_lateral_active = r->lateral;
 
    /*
     * Analyze and transform the subquery.  Note that if the subquery doesn't
     * have an alias, it can't be explicitly selected for locking, but locking
     * might still be required (if there is an all-tables locking clause).
     */
    query = parse_sub_analyze(r->subquery, pstate, NULL,
                              isLockedRefname(pstate,
                                              r->alias == NULL ? NULL :
                                              r->alias->aliasname),
                              true);
 
    /* Restore state */
    pstate->p_lateral_active = false;
    pstate->p_expr_kind = EXPR_KIND_NONE;
 
    /*
     * Check that we got a SELECT.  Anything else should be impossible given
     * restrictions of the grammar, but check anyway.
     */
    if (!IsA(query, Query) ||
        query->commandType != CMD_SELECT)
        elog(ERROR, "unexpected non-SELECT command in subquery in FROM");
 
    /*
     * OK, build an RTE and nsitem for the subquery.
     */
    return addRangeTableEntryForSubquery(pstate,
                                         query,
                                         r->alias,
                                         r->lateral,
                                         true);
}

References addRangeTableEntryForSubquery(), RangeSubselect::alias, Alias::aliasname, Assert, CMD_SELECT, Query::commandType, elog, ERROR, EXPR_KIND_FROM_SUBSELECT, EXPR_KIND_NONE, IsA, isLockedRefname(), RangeSubselect::lateral, ParseState::p_expr_kind, ParseState::p_lateral_active, parse_sub_analyze(), and RangeSubselect::subquery.

Referenced by transformFromClauseItem().

transformRangeTableFunc()

static ParseNamespaceItem * transformRangeTableFunc ( ParseState *  pstate, RangeTableFunc *  rtf  )

static

Definition at line 686 of file parse_clause.c.

{
    TableFunc  *tf = makeNode(TableFunc);
    const char *constructName;
    Oid         docType;
    bool        is_lateral;
    ListCell   *col;
    char      **names;
    int         colno;
 
    /*
     * Currently we only support XMLTABLE here.  See transformJsonTable() for
     * JSON_TABLE support.
     */
    tf->functype = TFT_XMLTABLE;
    constructName = "XMLTABLE";
    docType = XMLOID;
 
    /*
     * We make lateral_only names of this level visible, whether or not the
     * RangeTableFunc is explicitly marked LATERAL.  This is needed for SQL
     * spec compliance and seems useful on convenience grounds for all
     * functions in FROM.
     *
     * (LATERAL can't nest within a single pstate level, so we don't need
     * save/restore logic here.)
     */
    Assert(!pstate->p_lateral_active);
    pstate->p_lateral_active = true;
 
    /* Transform and apply typecast to the row-generating expression ... */
    Assert(rtf->rowexpr != NULL);
    tf->rowexpr = coerce_to_specific_type(pstate,
                                          transformExpr(pstate, rtf->rowexpr, EXPR_KIND_FROM_FUNCTION),
                                          TEXTOID,
                                          constructName);
    assign_expr_collations(pstate, tf->rowexpr);
 
    /* ... and to the document itself */
    Assert(rtf->docexpr != NULL);
    tf->docexpr = coerce_to_specific_type(pstate,
                                          transformExpr(pstate, rtf->docexpr, EXPR_KIND_FROM_FUNCTION),
                                          docType,
                                          constructName);
    assign_expr_collations(pstate, tf->docexpr);
 
    /* undef ordinality column number */
    tf->ordinalitycol = -1;
 
    /* Process column specs */
    names = palloc(sizeof(char *) * list_length(rtf->columns));
 
    colno = 0;
    foreach(col, rtf->columns)
    {
        RangeTableFuncCol *rawc = (RangeTableFuncCol *) lfirst(col);
        Oid         typid;
        int32       typmod;
        Node       *colexpr;
        Node       *coldefexpr;
        int         j;
 
        tf->colnames = lappend(tf->colnames,
                               makeString(pstrdup(rawc->colname)));
 
        /*
         * Determine the type and typmod for the new column. FOR ORDINALITY
         * columns are INTEGER per spec; the others are user-specified.
         */
        if (rawc->for_ordinality)
        {
            if (tf->ordinalitycol != -1)
                ereport(ERROR,
                        (errcode(ERRCODE_SYNTAX_ERROR),
                         errmsg("only one FOR ORDINALITY column is allowed"),
                         parser_errposition(pstate, rawc->location)));
 
            typid = INT4OID;
            typmod = -1;
            tf->ordinalitycol = colno;
        }
        else
        {
            if (rawc->typeName->setof)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
                         errmsg("column \"%s\" cannot be declared SETOF",
                                rawc->colname),
                         parser_errposition(pstate, rawc->location)));
 
            typenameTypeIdAndMod(pstate, rawc->typeName,
                                 &typid, &typmod);
        }
 
        tf->coltypes = lappend_oid(tf->coltypes, typid);
        tf->coltypmods = lappend_int(tf->coltypmods, typmod);
        tf->colcollations = lappend_oid(tf->colcollations,
                                        get_typcollation(typid));
 
        /* Transform the PATH and DEFAULT expressions */
        if (rawc->colexpr)
        {
            colexpr = coerce_to_specific_type(pstate,
                                              transformExpr(pstate, rawc->colexpr,
                                                            EXPR_KIND_FROM_FUNCTION),
                                              TEXTOID,
                                              constructName);
            assign_expr_collations(pstate, colexpr);
        }
        else
            colexpr = NULL;
 
        if (rawc->coldefexpr)
        {
            coldefexpr = coerce_to_specific_type_typmod(pstate,
                                                        transformExpr(pstate, rawc->coldefexpr,
                                                                      EXPR_KIND_FROM_FUNCTION),
                                                        typid, typmod,
                                                        constructName);
            assign_expr_collations(pstate, coldefexpr);
        }
        else
            coldefexpr = NULL;
 
        tf->colexprs = lappend(tf->colexprs, colexpr);
        tf->coldefexprs = lappend(tf->coldefexprs, coldefexpr);
 
        if (rawc->is_not_null)
            tf->notnulls = bms_add_member(tf->notnulls, colno);
 
        /* make sure column names are unique */
        for (j = 0; j < colno; j++)
            if (strcmp(names[j], rawc->colname) == 0)
                ereport(ERROR,
                        (errcode(ERRCODE_SYNTAX_ERROR),
                         errmsg("column name \"%s\" is not unique",
                                rawc->colname),
                         parser_errposition(pstate, rawc->location)));
        names[colno] = rawc->colname;
 
        colno++;
    }
    pfree(names);
 
    /* Namespaces, if any, also need to be transformed */
    if (rtf->namespaces != NIL)
    {
        ListCell   *ns;
        ListCell   *lc2;
        List       *ns_uris = NIL;
        List       *ns_names = NIL;
        bool        default_ns_seen = false;
 
        foreach(ns, rtf->namespaces)
        {
            ResTarget  *r = (ResTarget *) lfirst(ns);
            Node       *ns_uri;
 
            Assert(IsA(r, ResTarget));
            ns_uri = transformExpr(pstate, r->val, EXPR_KIND_FROM_FUNCTION);
            ns_uri = coerce_to_specific_type(pstate, ns_uri,
                                             TEXTOID, constructName);
            assign_expr_collations(pstate, ns_uri);
            ns_uris = lappend(ns_uris, ns_uri);
 
            /* Verify consistency of name list: no dupes, only one DEFAULT */
            if (r->name != NULL)
            {
                foreach(lc2, ns_names)
                {
                    String     *ns_node = lfirst_node(String, lc2);
 
                    if (ns_node == NULL)
                        continue;
                    if (strcmp(strVal(ns_node), r->name) == 0)
                        ereport(ERROR,
                                (errcode(ERRCODE_SYNTAX_ERROR),
                                 errmsg("namespace name \"%s\" is not unique",
                                        r->name),
                                 parser_errposition(pstate, r->location)));
                }
            }
            else
            {
                if (default_ns_seen)
                    ereport(ERROR,
                            (errcode(ERRCODE_SYNTAX_ERROR),
                             errmsg("only one default namespace is allowed"),
                             parser_errposition(pstate, r->location)));
                default_ns_seen = true;
            }
 
            /* We represent DEFAULT by a null pointer */
            ns_names = lappend(ns_names,
                               r->name ? makeString(r->name) : NULL);
        }
 
        tf->ns_uris = ns_uris;
        tf->ns_names = ns_names;
    }
 
    tf->location = rtf->location;
 
    pstate->p_lateral_active = false;
 
    /*
     * Mark the RTE as LATERAL if the user said LATERAL explicitly, or if
     * there are any lateral cross-references in it.
     */
    is_lateral = rtf->lateral || contain_vars_of_level((Node *) tf, 0);
 
    return addRangeTableEntryForTableFunc(pstate,
                                          tf, rtf->alias, is_lateral, true);
}

References addRangeTableEntryForTableFunc(), RangeTableFunc::alias, Assert, assign_expr_collations(), bms_add_member(), coerce_to_specific_type(), coerce_to_specific_type_typmod(), RangeTableFuncCol::coldefexpr, RangeTableFuncCol::colexpr, TableFunc::colexprs, RangeTableFuncCol::colname, RangeTableFunc::columns, contain_vars_of_level(), RangeTableFunc::docexpr, TableFunc::docexpr, ereport, errcode(), errmsg(), ERROR, EXPR_KIND_FROM_FUNCTION, RangeTableFuncCol::for_ordinality, TableFunc::functype, get_typcollation(), RangeTableFuncCol::is_not_null, IsA, j, lappend(), lappend_int(), lappend_oid(), RangeTableFunc::lateral, lfirst, lfirst_node, list_length(), ResTarget::location, RangeTableFunc::location, RangeTableFuncCol::location, TableFunc::location, makeNode, makeString(), ResTarget::name, RangeTableFunc::namespaces, NIL, ParseState::p_lateral_active, palloc(), parser_errposition(), pfree(), pstrdup(), RangeTableFunc::rowexpr, TableFunc::rowexpr, TypeName::setof, strVal, TFT_XMLTABLE, transformExpr(), RangeTableFuncCol::typeName, typenameTypeIdAndMod(), and ResTarget::val.

Referenced by transformFromClauseItem().

transformRangeTableSample()

static TableSampleClause * transformRangeTableSample ( ParseState *  pstate, RangeTableSample *  rts  )

static

Definition at line 908 of file parse_clause.c.

{
    TableSampleClause *tablesample;
    Oid         handlerOid;
    Oid         funcargtypes[1];
    TsmRoutine *tsm;
    List       *fargs;
    ListCell   *larg,
               *ltyp;
 
    /*
     * To validate the sample method name, look up the handler function, which
     * has the same name, one dummy INTERNAL argument, and a result type of
     * tsm_handler.  (Note: tablesample method names are not schema-qualified
     * in the SQL standard; but since they are just functions to us, we allow
     * schema qualification to resolve any potential ambiguity.)
     */
    funcargtypes[0] = INTERNALOID;
 
    handlerOid = LookupFuncName(rts->method, 1, funcargtypes, true);
 
    /* we want error to complain about no-such-method, not no-such-function */
    if (!OidIsValid(handlerOid))
        ereport(ERROR,
                (errcode(ERRCODE_UNDEFINED_OBJECT),
                 errmsg("tablesample method %s does not exist",
                        NameListToString(rts->method)),
                 parser_errposition(pstate, rts->location)));
 
    /* check that handler has correct return type */
    if (get_func_rettype(handlerOid) != TSM_HANDLEROID)
        ereport(ERROR,
                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                 errmsg("function %s must return type %s",
                        NameListToString(rts->method), "tsm_handler"),
                 parser_errposition(pstate, rts->location)));
 
    /* OK, run the handler to get TsmRoutine, for argument type info */
    tsm = GetTsmRoutine(handlerOid);
 
    tablesample = makeNode(TableSampleClause);
    tablesample->tsmhandler = handlerOid;
 
    /* check user provided the expected number of arguments */
    if (list_length(rts->args) != list_length(tsm->parameterTypes))
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_TABLESAMPLE_ARGUMENT),
                 errmsg_plural("tablesample method %s requires %d argument, not %d",
                               "tablesample method %s requires %d arguments, not %d",
                               list_length(tsm->parameterTypes),
                               NameListToString(rts->method),
                               list_length(tsm->parameterTypes),
                               list_length(rts->args)),
                 parser_errposition(pstate, rts->location)));
 
    /*
     * Transform the arguments, typecasting them as needed.  Note we must also
     * assign collations now, because assign_query_collations() doesn't
     * examine any substructure of RTEs.
     */
    fargs = NIL;
    forboth(larg, rts->args, ltyp, tsm->parameterTypes)
    {
        Node       *arg = (Node *) lfirst(larg);
        Oid         argtype = lfirst_oid(ltyp);
 
        arg = transformExpr(pstate, arg, EXPR_KIND_FROM_FUNCTION);
        arg = coerce_to_specific_type(pstate, arg, argtype, "TABLESAMPLE");
        assign_expr_collations(pstate, arg);
        fargs = lappend(fargs, arg);
    }
    tablesample->args = fargs;
 
    /* Process REPEATABLE (seed) */
    if (rts->repeatable != NULL)
    {
        Node       *arg;
 
        if (!tsm->repeatable_across_queries)
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("tablesample method %s does not support REPEATABLE",
                            NameListToString(rts->method)),
                     parser_errposition(pstate, rts->location)));
 
        arg = transformExpr(pstate, rts->repeatable, EXPR_KIND_FROM_FUNCTION);
        arg = coerce_to_specific_type(pstate, arg, FLOAT8OID, "REPEATABLE");
        assign_expr_collations(pstate, arg);
        tablesample->repeatable = (Expr *) arg;
    }
    else
        tablesample->repeatable = NULL;
 
    return tablesample;
}

References arg, RangeTableSample::args, TableSampleClause::args, assign_expr_collations(), coerce_to_specific_type(), ereport, errcode(), errmsg(), errmsg_plural(), ERROR, EXPR_KIND_FROM_FUNCTION, forboth, get_func_rettype(), GetTsmRoutine(), lappend(), lfirst, lfirst_oid, list_length(), RangeTableSample::location, LookupFuncName(), makeNode, RangeTableSample::method, NameListToString(), NIL, OidIsValid, TsmRoutine::parameterTypes, parser_errposition(), RangeTableSample::repeatable, TableSampleClause::repeatable, TsmRoutine::repeatable_across_queries, transformExpr(), and TableSampleClause::tsmhandler.

Referenced by transformFromClauseItem().

transformSortClause()

List * transformSortClause	(	ParseState *	pstate,
		List *	orderlist,
		List **	targetlist,
		ParseExprKind	exprKind,
		bool	useSQL99
	)

Definition at line 2732 of file parse_clause.c.

{
    List       *sortlist = NIL;
    ListCell   *olitem;
 
    foreach(olitem, orderlist)
    {
        SortBy     *sortby = (SortBy *) lfirst(olitem);
        TargetEntry *tle;
 
        if (useSQL99)
            tle = findTargetlistEntrySQL99(pstate, sortby->node,
                                           targetlist, exprKind);
        else
            tle = findTargetlistEntrySQL92(pstate, sortby->node,
                                           targetlist, exprKind);
 
        sortlist = addTargetToSortList(pstate, tle,
                                       sortlist, *targetlist, sortby);
    }
 
    return sortlist;
}

References addTargetToSortList(), findTargetlistEntrySQL92(), findTargetlistEntrySQL99(), lfirst, NIL, and SortBy::node.

Referenced by transformAggregateCall(), transformPLAssignStmt(), transformSelectStmt(), transformSetOperationStmt(), transformValuesClause(), and transformWindowDefinitions().

transformTableEntry()

static ParseNamespaceItem * transformTableEntry ( ParseState *  pstate, RangeVar *  r  )

static

Definition at line 395 of file parse_clause.c.

{
    /* addRangeTableEntry does all the work */
    return addRangeTableEntry(pstate, r, r->alias, r->inh, true);
}

References addRangeTableEntry(), RangeVar::alias, and RangeVar::inh.

Referenced by transformFromClauseItem().

transformWhereClause()

Node * transformWhereClause	(	ParseState *	pstate,
		Node *	clause,
		ParseExprKind	exprKind,
		const char *	constructName
	)

Definition at line 1854 of file parse_clause.c.

{
    Node       *qual;
 
    if (clause == NULL)
        return NULL;
 
    qual = transformExpr(pstate, clause, exprKind);
 
    qual = coerce_to_boolean(pstate, qual, constructName);
 
    return qual;
}

References coerce_to_boolean(), and transformExpr().

Referenced by AlterPolicy(), CreatePolicy(), CreateTriggerFiringOn(), ParseFuncOrColumn(), test_rls_hooks_permissive(), test_rls_hooks_restrictive(), transformDeleteStmt(), transformIndexStmt(), transformJoinOnClause(), transformJsonAggConstructor(), transformMergeStmt(), transformOnConflictClause(), transformPLAssignStmt(), TransformPubWhereClauses(), transformRuleStmt(), transformSelectStmt(), and transformUpdateStmt().

transformWindowDefinitions()

List * transformWindowDefinitions	(	ParseState *	pstate,
		List *	windowdefs,
		List **	targetlist
	)

Definition at line 2765 of file parse_clause.c.

{
    List       *result = NIL;
    Index       winref = 0;
    ListCell   *lc;
 
    foreach(lc, windowdefs)
    {
        WindowDef  *windef = (WindowDef *) lfirst(lc);
        WindowClause *refwc = NULL;
        List       *partitionClause;
        List       *orderClause;
        Oid         rangeopfamily = InvalidOid;
        Oid         rangeopcintype = InvalidOid;
        WindowClause *wc;
 
        winref++;
 
        /*
         * Check for duplicate window names.
         */
        if (windef->name &&
            findWindowClause(result, windef->name) != NULL)
            ereport(ERROR,
                    (errcode(ERRCODE_WINDOWING_ERROR),
                     errmsg("window \"%s\" is already defined", windef->name),
                     parser_errposition(pstate, windef->location)));
 
        /*
         * If it references a previous window, look that up.
         */
        if (windef->refname)
        {
            refwc = findWindowClause(result, windef->refname);
            if (refwc == NULL)
                ereport(ERROR,
                        (errcode(ERRCODE_UNDEFINED_OBJECT),
                         errmsg("window \"%s\" does not exist",
                                windef->refname),
                         parser_errposition(pstate, windef->location)));
        }
 
        /*
         * Transform PARTITION and ORDER specs, if any.  These are treated
         * almost exactly like top-level GROUP BY and ORDER BY clauses,
         * including the special handling of nondefault operator semantics.
         */
        orderClause = transformSortClause(pstate,
                                          windef->orderClause,
                                          targetlist,
                                          EXPR_KIND_WINDOW_ORDER,
                                          true /* force SQL99 rules */ );
        partitionClause = transformGroupClause(pstate,
                                               windef->partitionClause,
                                               NULL,
                                               targetlist,
                                               orderClause,
                                               EXPR_KIND_WINDOW_PARTITION,
                                               true /* force SQL99 rules */ );
 
        /*
         * And prepare the new WindowClause.
         */
        wc = makeNode(WindowClause);
        wc->name = windef->name;
        wc->refname = windef->refname;
 
        /*
         * Per spec, a windowdef that references a previous one copies the
         * previous partition clause (and mustn't specify its own).  It can
         * specify its own ordering clause, but only if the previous one had
         * none.  It always specifies its own frame clause, and the previous
         * one must not have a frame clause.  Yeah, it's bizarre that each of
         * these cases works differently, but SQL:2008 says so; see 7.11
         * <window clause> syntax rule 10 and general rule 1.  The frame
         * clause rule is especially bizarre because it makes "OVER foo"
         * different from "OVER (foo)", and requires the latter to throw an
         * error if foo has a nondefault frame clause.  Well, ours not to
         * reason why, but we do go out of our way to throw a useful error
         * message for such cases.
         */
        if (refwc)
        {
            if (partitionClause)
                ereport(ERROR,
                        (errcode(ERRCODE_WINDOWING_ERROR),
                         errmsg("cannot override PARTITION BY clause of window \"%s\"",
                                windef->refname),
                         parser_errposition(pstate, windef->location)));
            wc->partitionClause = copyObject(refwc->partitionClause);
        }
        else
            wc->partitionClause = partitionClause;
        if (refwc)
        {
            if (orderClause && refwc->orderClause)
                ereport(ERROR,
                        (errcode(ERRCODE_WINDOWING_ERROR),
                         errmsg("cannot override ORDER BY clause of window \"%s\"",
                                windef->refname),
                         parser_errposition(pstate, windef->location)));
            if (orderClause)
            {
                wc->orderClause = orderClause;
                wc->copiedOrder = false;
            }
            else
            {
                wc->orderClause = copyObject(refwc->orderClause);
                wc->copiedOrder = true;
            }
        }
        else
        {
            wc->orderClause = orderClause;
            wc->copiedOrder = false;
        }
        if (refwc && refwc->frameOptions != FRAMEOPTION_DEFAULTS)
        {
            /*
             * Use this message if this is a WINDOW clause, or if it's an OVER
             * clause that includes ORDER BY or framing clauses.  (We already
             * rejected PARTITION BY above, so no need to check that.)
             */
            if (windef->name ||
                orderClause || windef->frameOptions != FRAMEOPTION_DEFAULTS)
                ereport(ERROR,
                        (errcode(ERRCODE_WINDOWING_ERROR),
                         errmsg("cannot copy window \"%s\" because it has a frame clause",
                                windef->refname),
                         parser_errposition(pstate, windef->location)));
            /* Else this clause is just OVER (foo), so say this: */
            ereport(ERROR,
                    (errcode(ERRCODE_WINDOWING_ERROR),
                     errmsg("cannot copy window \"%s\" because it has a frame clause",
                            windef->refname),
                     errhint("Omit the parentheses in this OVER clause."),
                     parser_errposition(pstate, windef->location)));
        }
        wc->frameOptions = windef->frameOptions;
 
        /*
         * RANGE offset PRECEDING/FOLLOWING requires exactly one ORDER BY
         * column; check that and get its sort opfamily info.
         */
        if ((wc->frameOptions & FRAMEOPTION_RANGE) &&
            (wc->frameOptions & (FRAMEOPTION_START_OFFSET |
                                 FRAMEOPTION_END_OFFSET)))
        {
            SortGroupClause *sortcl;
            Node       *sortkey;
            int16       rangestrategy;
 
            if (list_length(wc->orderClause) != 1)
                ereport(ERROR,
                        (errcode(ERRCODE_WINDOWING_ERROR),
                         errmsg("RANGE with offset PRECEDING/FOLLOWING requires exactly one ORDER BY column"),
                         parser_errposition(pstate, windef->location)));
            sortcl = linitial_node(SortGroupClause, wc->orderClause);
            sortkey = get_sortgroupclause_expr(sortcl, *targetlist);
            /* Find the sort operator in pg_amop */
            if (!get_ordering_op_properties(sortcl->sortop,
                                            &rangeopfamily,
                                            &rangeopcintype,
                                            &rangestrategy))
                elog(ERROR, "operator %u is not a valid ordering operator",
                     sortcl->sortop);
            /* Record properties of sort ordering */
            wc->inRangeColl = exprCollation(sortkey);
            wc->inRangeAsc = !sortcl->reverse_sort;
            wc->inRangeNullsFirst = sortcl->nulls_first;
        }
 
        /* Per spec, GROUPS mode requires an ORDER BY clause */
        if (wc->frameOptions & FRAMEOPTION_GROUPS)
        {
            if (wc->orderClause == NIL)
                ereport(ERROR,
                        (errcode(ERRCODE_WINDOWING_ERROR),
                         errmsg("GROUPS mode requires an ORDER BY clause"),
                         parser_errposition(pstate, windef->location)));
        }
 
        /* Process frame offset expressions */
        wc->startOffset = transformFrameOffset(pstate, wc->frameOptions,
                                               rangeopfamily, rangeopcintype,
                                               &wc->startInRangeFunc,
                                               windef->startOffset);
        wc->endOffset = transformFrameOffset(pstate, wc->frameOptions,
                                             rangeopfamily, rangeopcintype,
                                             &wc->endInRangeFunc,
                                             windef->endOffset);
        wc->winref = winref;
 
        result = lappend(result, wc);
    }
 
    return result;
}

References copyObject, elog, WindowDef::endOffset, WindowClause::endOffset, ereport, errcode(), errhint(), errmsg(), ERROR, EXPR_KIND_WINDOW_ORDER, EXPR_KIND_WINDOW_PARTITION, exprCollation(), findWindowClause(), FRAMEOPTION_DEFAULTS, FRAMEOPTION_END_OFFSET, FRAMEOPTION_GROUPS, FRAMEOPTION_RANGE, FRAMEOPTION_START_OFFSET, WindowDef::frameOptions, WindowClause::frameOptions, get_ordering_op_properties(), get_sortgroupclause_expr(), InvalidOid, lappend(), lfirst, linitial_node, list_length(), WindowDef::location, makeNode, WindowDef::name, NIL, SortGroupClause::nulls_first, WindowDef::orderClause, WindowClause::orderClause, parser_errposition(), WindowDef::partitionClause, WindowClause::partitionClause, WindowDef::refname, SortGroupClause::reverse_sort, SortGroupClause::sortop, WindowDef::startOffset, WindowClause::startOffset, transformFrameOffset(), transformGroupClause(), transformSortClause(), and WindowClause::winref.

Referenced by transformPLAssignStmt(), and transformSelectStmt().