diff options
Diffstat (limited to 'src/backend/parser/parse_expr.c')
| -rw-r--r-- | src/backend/parser/parse_expr.c | 72 |
1 files changed, 71 insertions, 1 deletions
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 6d5f21b52ef..fdb4c4dcf25 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.183 2005/06/04 20:56:13 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.184 2005/06/26 22:05:39 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -53,6 +53,7 @@ static Node *transformSubLink(ParseState *pstate, SubLink *sublink); static Node *transformArrayExpr(ParseState *pstate, ArrayExpr *a); static Node *transformRowExpr(ParseState *pstate, RowExpr *r); static Node *transformCoalesceExpr(ParseState *pstate, CoalesceExpr *c); +static Node *transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m); static Node *transformBooleanTest(ParseState *pstate, BooleanTest *b); static Node *transformColumnRef(ParseState *pstate, ColumnRef *cref); static Node *transformWholeRowRef(ParseState *pstate, char *schemaname, @@ -209,6 +210,10 @@ transformExpr(ParseState *pstate, Node *expr) result = transformCoalesceExpr(pstate, (CoalesceExpr *) expr); break; + case T_MinMaxExpr: + result = transformMinMaxExpr(pstate, (MinMaxExpr *) expr); + break; + case T_NullTest: { NullTest *n = (NullTest *) expr; @@ -1230,6 +1235,44 @@ transformCoalesceExpr(ParseState *pstate, CoalesceExpr *c) } static Node * +transformMinMaxExpr(ParseState *pstate, MinMaxExpr *m) +{ + MinMaxExpr *newm = makeNode(MinMaxExpr); + List *newargs = NIL; + List *newcoercedargs = NIL; + List *typeids = NIL; + ListCell *args; + + newm->op = m->op; + foreach(args, m->args) + { + Node *e = (Node *) lfirst(args); + Node *newe; + + newe = transformExpr(pstate, e); + newargs = lappend(newargs, newe); + typeids = lappend_oid(typeids, exprType(newe)); + } + + newm->minmaxtype = select_common_type(typeids, "GREATEST/LEAST"); + + /* Convert arguments if necessary */ + foreach(args, newargs) + { + Node *e = (Node *) lfirst(args); + Node *newe; + + newe = coerce_to_common_type(pstate, e, + newm->minmaxtype, + "GREATEST/LEAST"); + newcoercedargs = lappend(newcoercedargs, newe); + } + + newm->args = newcoercedargs; + return (Node *) newm; +} + +static Node * transformBooleanTest(ParseState *pstate, BooleanTest *b) { const char *clausename; @@ -1503,6 +1546,9 @@ exprType(Node *expr) case T_CoalesceExpr: type = ((CoalesceExpr *) expr)->coalescetype; break; + case T_MinMaxExpr: + type = ((MinMaxExpr *) expr)->minmaxtype; + break; case T_NullIfExpr: type = exprType((Node *) linitial(((NullIfExpr *) expr)->args)); break; @@ -1637,6 +1683,30 @@ exprTypmod(Node *expr) return typmod; } break; + case T_MinMaxExpr: + { + /* + * If all the alternatives agree on type/typmod, return + * that typmod, else use -1 + */ + MinMaxExpr *mexpr = (MinMaxExpr *) expr; + Oid minmaxtype = mexpr->minmaxtype; + int32 typmod; + ListCell *arg; + + typmod = exprTypmod((Node *) linitial(mexpr->args)); + foreach(arg, mexpr->args) + { + Node *e = (Node *) lfirst(arg); + + if (exprType(e) != minmaxtype) + return -1; + if (exprTypmod(e) != typmod) + return -1; + } + return typmod; + } + break; case T_NullIfExpr: { NullIfExpr *nexpr = (NullIfExpr *) expr; |