diff options
Diffstat (limited to 'src/backend/parser/parse_expr.c')
| -rw-r--r-- | src/backend/parser/parse_expr.c | 62 |
1 files changed, 38 insertions, 24 deletions
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index c23e39a25d0..3881cc39538 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 1.165 2004/02/13 01:08:20 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.166 2004/03/17 20:48:42 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -637,14 +637,39 @@ transformExpr(ParseState *pstate, Node *expr) case T_CaseExpr: { CaseExpr *c = (CaseExpr *) expr; - CaseExpr *newc = makeNode(CaseExpr); - List *newargs = NIL; - List *typeids = NIL; + CaseExpr *newc; + Node *arg; + CaseTestExpr *placeholder; + List *newargs; + List *typeids; List *args; Node *defresult; Oid ptype; + /* If we already transformed this node, do nothing */ + if (OidIsValid(c->casetype)) + { + result = expr; + break; + } + newc = makeNode(CaseExpr); + + /* transform the test expression, if any */ + arg = transformExpr(pstate, (Node *) c->arg); + newc->arg = (Expr *) arg; + /* generate placeholder for test expression */ + if (arg) + { + placeholder = makeNode(CaseTestExpr); + placeholder->typeId = exprType(arg); + placeholder->typeMod = exprTypmod(arg); + } + else + placeholder = NULL; + /* transform the list of arguments */ + newargs = NIL; + typeids = NIL; foreach(args, c->args) { CaseWhen *w = (CaseWhen *) lfirst(args); @@ -654,11 +679,11 @@ transformExpr(ParseState *pstate, Node *expr) Assert(IsA(w, CaseWhen)); warg = (Node *) w->expr; - if (c->arg != NULL) + if (placeholder) { /* shorthand form was specified, so expand... */ warg = (Node *) makeSimpleA_Expr(AEXPR_OP, "=", - (Node *) c->arg, + (Node *) placeholder, warg); } neww->expr = (Expr *) transformExpr(pstate, warg); @@ -667,18 +692,7 @@ transformExpr(ParseState *pstate, Node *expr) (Node *) neww->expr, "CASE/WHEN"); - /* - * result is NULL for NULLIF() construct - thomas - * 1998-11-11 - */ warg = (Node *) w->result; - if (warg == NULL) - { - A_Const *n = makeNode(A_Const); - - n->val.type = T_Null; - warg = (Node *) n; - } neww->result = (Expr *) transformExpr(pstate, warg); newargs = lappend(newargs, neww); @@ -687,13 +701,6 @@ transformExpr(ParseState *pstate, Node *expr) newc->args = newargs; - /* - * It's not shorthand anymore, so drop the implicit - * argument. This is necessary to keep any re-application - * of transformExpr from doing the wrong thing. - */ - newc->arg = NULL; - /* transform the default clause */ defresult = (Node *) c->defresult; if (defresult == NULL) @@ -714,6 +721,7 @@ transformExpr(ParseState *pstate, Node *expr) typeids = lconso(exprType((Node *) newc->defresult), typeids); ptype = select_common_type(typeids, "CASE"); + Assert(OidIsValid(ptype)); newc->casetype = ptype; /* Convert default result clause, if necessary */ @@ -915,6 +923,7 @@ transformExpr(ParseState *pstate, Node *expr) case T_BoolExpr: case T_FieldSelect: case T_RelabelType: + case T_CaseTestExpr: case T_CoerceToDomain: case T_CoerceToDomainValue: case T_SetToDefault: @@ -1288,6 +1297,9 @@ exprType(Node *expr) case T_CaseWhen: type = exprType((Node *) ((CaseWhen *) expr)->result); break; + case T_CaseTestExpr: + type = ((CaseTestExpr *) expr)->typeId; + break; case T_ArrayExpr: type = ((ArrayExpr *) expr)->array_typeid; break; @@ -1408,6 +1420,8 @@ exprTypmod(Node *expr) return typmod; } break; + case T_CaseTestExpr: + return ((CaseTestExpr *) expr)->typeMod; case T_CoalesceExpr: { /* |