diff options
Diffstat (limited to 'src/backend/executor/execQual.c')
| -rw-r--r-- | src/backend/executor/execQual.c | 140 |
1 files changed, 135 insertions, 5 deletions
diff --git a/src/backend/executor/execQual.c b/src/backend/executor/execQual.c index a2583fcc4c9..968617c39a9 100644 --- a/src/backend/executor/execQual.c +++ b/src/backend/executor/execQual.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/executor/execQual.c,v 1.124 2003/02/03 21:15:43 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/executor/execQual.c,v 1.125 2003/02/16 02:30:37 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -64,7 +64,7 @@ static Datum ExecEvalFunc(FuncExprState *fcache, ExprContext *econtext, static Datum ExecEvalOper(FuncExprState *fcache, ExprContext *econtext, bool *isNull, ExprDoneCond *isDone); static Datum ExecEvalDistinct(FuncExprState *fcache, ExprContext *econtext, - bool *isNull, ExprDoneCond *isDone); + bool *isNull); static ExprDoneCond ExecEvalFuncArgs(FunctionCallInfo fcinfo, List *argList, ExprContext *econtext); static Datum ExecEvalNot(BoolExprState *notclause, ExprContext *econtext, @@ -75,6 +75,11 @@ static Datum ExecEvalAnd(BoolExprState *andExpr, ExprContext *econtext, bool *isNull); static Datum ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext, bool *isNull, ExprDoneCond *isDone); +static Datum ExecEvalCoalesce(CoalesceExprState *coalesceExpr, + ExprContext *econtext, + bool *isNull); +static Datum ExecEvalNullIf(FuncExprState *nullIfExpr, ExprContext *econtext, + bool *isNull); static Datum ExecEvalNullTest(GenericExprState *nstate, ExprContext *econtext, bool *isNull, ExprDoneCond *isDone); @@ -1187,8 +1192,7 @@ ExecEvalOper(FuncExprState *fcache, static Datum ExecEvalDistinct(FuncExprState *fcache, ExprContext *econtext, - bool *isNull, - ExprDoneCond *isDone) + bool *isNull) { Datum result; FunctionCallInfoData fcinfo; @@ -1370,6 +1374,7 @@ ExecEvalAnd(BoolExprState *andExpr, ExprContext *econtext, bool *isNull) return BoolGetDatum(!AnyNull); } + /* ---------------------------------------------------------------- * ExecEvalCase * @@ -1430,6 +1435,91 @@ ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext, } /* ---------------------------------------------------------------- + * ExecEvalCoalesce + * ---------------------------------------------------------------- + */ +static Datum +ExecEvalCoalesce(CoalesceExprState *coalesceExpr, ExprContext *econtext, + bool *isNull) +{ + List *arg; + + /* Simply loop through until something NOT NULL is found */ + foreach(arg, coalesceExpr->args) + { + ExprState *e = (ExprState *) lfirst(arg); + Datum value; + + value = ExecEvalExpr(e, econtext, isNull, NULL); + if (!*isNull) + return value; + } + + /* Else return NULL */ + *isNull = true; + return (Datum) 0; +} + +/* ---------------------------------------------------------------- + * ExecEvalNullIf + * + * Note that this is *always* derived from the equals operator, + * but since we need special processing of the arguments + * we can not simply reuse ExecEvalOper() or ExecEvalFunc(). + * ---------------------------------------------------------------- + */ +static Datum +ExecEvalNullIf(FuncExprState *fcache, ExprContext *econtext, + bool *isNull) +{ + Datum result; + FunctionCallInfoData fcinfo; + ExprDoneCond argDone; + List *argList; + + /* + * Initialize function cache if first time through + */ + if (fcache->func.fn_oid == InvalidOid) + { + NullIfExpr *op = (NullIfExpr *) fcache->xprstate.expr; + + init_fcache(op->opfuncid, fcache, econtext->ecxt_per_query_memory); + Assert(!fcache->func.fn_retset); + } + + /* + * extract info from fcache + */ + argList = fcache->args; + + /* Need to prep callinfo structure */ + MemSet(&fcinfo, 0, sizeof(fcinfo)); + fcinfo.flinfo = &(fcache->func); + argDone = ExecEvalFuncArgs(&fcinfo, argList, econtext); + if (argDone != ExprSingleResult) + elog(ERROR, "NULLIF does not support set arguments"); + Assert(fcinfo.nargs == 2); + + /* if either argument is NULL they can't be equal */ + if (!fcinfo.argnull[0] && !fcinfo.argnull[1]) + { + fcinfo.isnull = false; + result = FunctionCallInvoke(&fcinfo); + /* if the arguments are equal return null */ + if (!fcinfo.isnull && DatumGetBool(result)) + { + *isNull = true; + return (Datum) 0; + } + } + + /* else return first argument */ + *isNull = fcinfo.argnull[0]; + return fcinfo.arg[0]; +} + +/* ---------------------------------------------------------------- * ExecEvalNullTest * * Evaluate a NullTest node. @@ -1778,7 +1868,7 @@ ExecEvalExpr(ExprState *expression, break; case T_DistinctExpr: retDatum = ExecEvalDistinct((FuncExprState *) expression, econtext, - isNull, isDone); + isNull); break; case T_BoolExpr: { @@ -1826,6 +1916,16 @@ ExecEvalExpr(ExprState *expression, isNull, isDone); break; + case T_CoalesceExpr: + retDatum = ExecEvalCoalesce((CoalesceExprState *) expression, + econtext, + isNull); + break; + case T_NullIfExpr: + retDatum = ExecEvalNullIf((FuncExprState *) expression, + econtext, + isNull); + break; case T_NullTest: retDatum = ExecEvalNullTest((GenericExprState *) expression, econtext, @@ -2082,6 +2182,36 @@ ExecInitExpr(Expr *node, PlanState *parent) state = (ExprState *) cstate; } break; + case T_CoalesceExpr: + { + CoalesceExpr *coalesceexpr = (CoalesceExpr *) node; + CoalesceExprState *cstate = makeNode(CoalesceExprState); + List *outlist = NIL; + List *inlist; + + foreach(inlist, coalesceexpr->args) + { + Expr *e = (Expr *) lfirst(inlist); + ExprState *estate; + + estate = ExecInitExpr(e, parent); + outlist = lappend(outlist, estate); + } + cstate->args = outlist; + state = (ExprState *) cstate; + } + break; + case T_NullIfExpr: + { + NullIfExpr *nullifexpr = (NullIfExpr *) node; + FuncExprState *fstate = makeNode(FuncExprState); + + fstate->args = (List *) + ExecInitExpr((Expr *) nullifexpr->args, parent); + fstate->func.fn_oid = InvalidOid; /* not initialized */ + state = (ExprState *) fstate; + } + break; case T_NullTest: { NullTest *ntest = (NullTest *) node; |