diff options
Diffstat (limited to 'src/backend/executor/execQual.c')
| -rw-r--r-- | src/backend/executor/execQual.c | 52 |
1 files changed, 49 insertions, 3 deletions
diff --git a/src/backend/executor/execQual.c b/src/backend/executor/execQual.c index 94a5c110d41..fc16cccdda9 100644 --- a/src/backend/executor/execQual.c +++ b/src/backend/executor/execQual.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.155 2004/03/17 01:02:23 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.156 2004/03/17 20:48:42 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -81,6 +81,9 @@ static Datum ExecEvalAnd(BoolExprState *andExpr, ExprContext *econtext, bool *isNull, ExprDoneCond *isDone); static Datum ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext, bool *isNull, ExprDoneCond *isDone); +static Datum ExecEvalCaseTestExpr(ExprState *exprstate, + ExprContext *econtext, + bool *isNull, ExprDoneCond *isDone); static Datum ExecEvalArray(ArrayExprState *astate, ExprContext *econtext, bool *isNull, ExprDoneCond *isDone); @@ -1809,11 +1812,30 @@ ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext, { List *clauses = caseExpr->args; List *clause; + Datum save_datum; + bool save_isNull; if (isDone) *isDone = ExprSingleResult; /* + * If there's a test expression, we have to evaluate it and save + * the value where the CaseTestExpr placeholders can find it. + * We must save and restore prior setting of econtext's caseValue fields, + * in case this node is itself within a larger CASE. + */ + save_datum = econtext->caseValue_datum; + save_isNull = econtext->caseValue_isNull; + + if (caseExpr->arg) + { + econtext->caseValue_datum = ExecEvalExpr(caseExpr->arg, + econtext, + &econtext->caseValue_isNull, + NULL); + } + + /* * we evaluate each of the WHEN clauses in turn, as soon as one is * true we return the corresponding result. If none are true then we * return the value of the default clause, or NULL if there is none. @@ -1835,6 +1857,8 @@ ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext, */ if (DatumGetBool(clause_value) && !*isNull) { + econtext->caseValue_datum = save_datum; + econtext->caseValue_isNull = save_isNull; return ExecEvalExpr(wclause->result, econtext, isNull, @@ -1842,6 +1866,9 @@ ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext, } } + econtext->caseValue_datum = save_datum; + econtext->caseValue_isNull = save_isNull; + if (caseExpr->defresult) { return ExecEvalExpr(caseExpr->defresult, @@ -1854,6 +1881,22 @@ ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext, return (Datum) 0; } +/* + * ExecEvalCaseTestExpr + * + * Return the value stored by CASE. + */ +static Datum +ExecEvalCaseTestExpr(ExprState *exprstate, + ExprContext *econtext, + bool *isNull, ExprDoneCond *isDone) +{ + if (isDone) + *isDone = ExprSingleResult; + *isNull = econtext->caseValue_isNull; + return econtext->caseValue_datum; +} + /* ---------------------------------------------------------------- * ExecEvalArray - ARRAY[] expressions * @@ -2478,6 +2521,10 @@ ExecInitExpr(Expr *node, PlanState *parent) state = (ExprState *) makeNode(ExprState); state->evalfunc = ExecEvalCoerceToDomainValue; break; + case T_CaseTestExpr: + state = (ExprState *) makeNode(ExprState); + state->evalfunc = ExecEvalCaseTestExpr; + break; case T_Aggref: { Aggref *aggref = (Aggref *) node; @@ -2666,6 +2713,7 @@ ExecInitExpr(Expr *node, PlanState *parent) List *inlist; cstate->xprstate.evalfunc = (ExprStateEvalFunc) ExecEvalCase; + cstate->arg = ExecInitExpr(caseexpr->arg, parent); FastListInit(&outlist); foreach(inlist, caseexpr->args) { @@ -2680,8 +2728,6 @@ ExecInitExpr(Expr *node, PlanState *parent) FastAppend(&outlist, wstate); } cstate->args = FastListValue(&outlist); - /* caseexpr->arg should be null by now */ - Assert(caseexpr->arg == NULL); cstate->defresult = ExecInitExpr(caseexpr->defresult, parent); state = (ExprState *) cstate; } |