diff options
Diffstat (limited to 'src/backend/parser/parse_clause.c')
| -rw-r--r-- | src/backend/parser/parse_clause.c | 85 |
1 files changed, 81 insertions, 4 deletions
diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c index 6df4a4fd7dc..19aa688ff94 100644 --- a/src/backend/parser/parse_clause.c +++ b/src/backend/parser/parse_clause.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.90 2002/04/28 19:54:28 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.91 2002/05/12 20:10:04 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -17,6 +17,7 @@ #include "access/heapam.h" #include "nodes/makefuncs.h" +#include "optimizer/clauses.h" #include "optimizer/tlist.h" #include "optimizer/var.h" #include "parser/analyze.h" @@ -49,6 +50,8 @@ static Node *transformJoinOnClause(ParseState *pstate, JoinExpr *j, static RangeTblRef *transformTableEntry(ParseState *pstate, RangeVar *r); static RangeTblRef *transformRangeSubselect(ParseState *pstate, RangeSubselect *r); +static RangeTblRef *transformRangeFunction(ParseState *pstate, + RangeFunction *r); static Node *transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels); static Node *buildMergedJoinVar(JoinType jointype, @@ -82,9 +85,9 @@ transformFromClause(ParseState *pstate, List *frmList) /* * The grammar will have produced a list of RangeVars, - * RangeSubselects, 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. + * 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. */ foreach(fl, frmList) { @@ -454,6 +457,71 @@ transformRangeSubselect(ParseState *pstate, RangeSubselect *r) /* + * transformRangeFunction --- transform a function call appearing in FROM + */ +static RangeTblRef * +transformRangeFunction(ParseState *pstate, RangeFunction *r) +{ + Node *funcexpr; + char *funcname; + RangeTblEntry *rte; + RangeTblRef *rtr; + + /* + * Transform the raw FuncCall node + */ + funcexpr = transformExpr(pstate, r->funccallnode); + + Assert(IsA(r->funccallnode, FuncCall)); + funcname = strVal(llast(((FuncCall *) r->funccallnode)->funcname)); + + /* + * Disallow aggregate functions and subselects in the expression. + * (Aggregates clearly make no sense; perhaps later we could support + * subselects, though.) + */ + if (contain_agg_clause(funcexpr)) + elog(ERROR, "cannot use aggregate function in FROM function expression"); + if (contain_subplans(funcexpr)) + elog(ERROR, "cannot use subselect in FROM function expression"); + + /* + * Remove any Iter nodes added by parse_func.c. We oughta get rid of + * Iter completely ... + */ + while (funcexpr && IsA(funcexpr, Iter)) + funcexpr = ((Iter *) funcexpr)->iterexpr; + + /* + * Insist we now have a bare function call (explain.c is the only place + * that depends on this, I think). If this fails, it's probably because + * transformExpr interpreted the function notation as a type coercion. + */ + if (!funcexpr || + !IsA(funcexpr, Expr) || + ((Expr *) funcexpr)->opType != FUNC_EXPR) + elog(ERROR, "Coercion function not allowed in FROM clause"); + + /* + * OK, build an RTE for the function. + */ + rte = addRangeTableEntryForFunction(pstate, funcname, funcexpr, + r->alias, true); + + /* + * We create a RangeTblRef, but we do not add it to the joinlist or + * namespace; our caller must do that if appropriate. + */ + rtr = makeNode(RangeTblRef); + /* assume new rte is at end */ + rtr->rtindex = length(pstate->p_rtable); + Assert(rte == rt_fetch(rtr->rtindex, pstate->p_rtable)); + + return rtr; +} + + +/* * transformFromClauseItem - * Transform a FROM-clause item, adding any required entries to the * range table list being built in the ParseState, and return the @@ -486,6 +554,15 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels) *containedRels = makeListi1(rtr->rtindex); return (Node *) rtr; } + else if (IsA(n, RangeFunction)) + { + /* function is like a plain relation */ + RangeTblRef *rtr; + + rtr = transformRangeFunction(pstate, (RangeFunction *) n); + *containedRels = makeListi1(rtr->rtindex); + return (Node *) rtr; + } else if (IsA(n, JoinExpr)) { /* A newfangled join expression */ |