diff options
Diffstat (limited to 'src/backend/parser/parse_expr.c')
| -rw-r--r-- | src/backend/parser/parse_expr.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index f0f0488c57a..67a2310ad0e 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -48,6 +48,7 @@ static Node *transformAExprDistinct(ParseState *pstate, A_Expr *a); static Node *transformAExprNullIf(ParseState *pstate, A_Expr *a); static Node *transformAExprOf(ParseState *pstate, A_Expr *a); static Node *transformAExprIn(ParseState *pstate, A_Expr *a); +static Node *transformAExprBetween(ParseState *pstate, A_Expr *a); static Node *transformBoolExpr(ParseState *pstate, BoolExpr *a); static Node *transformFuncCall(ParseState *pstate, FuncCall *fn); static Node *transformMultiAssignRef(ParseState *pstate, MultiAssignRef *maref); @@ -241,6 +242,12 @@ transformExprRecurse(ParseState *pstate, Node *expr) case AEXPR_IN: result = transformAExprIn(pstate, a); break; + case AEXPR_BETWEEN: + case AEXPR_NOT_BETWEEN: + case AEXPR_BETWEEN_SYM: + case AEXPR_NOT_BETWEEN_SYM: + result = transformAExprBetween(pstate, a); + break; default: elog(ERROR, "unrecognized A_Expr kind: %d", a->kind); result = NULL; /* keep compiler quiet */ @@ -1196,6 +1203,101 @@ transformAExprIn(ParseState *pstate, A_Expr *a) } static Node * +transformAExprBetween(ParseState *pstate, A_Expr *a) +{ + Node *aexpr; + Node *bexpr; + Node *cexpr; + Node *result; + Node *sub1; + Node *sub2; + List *args; + + /* Deconstruct A_Expr into three subexprs */ + aexpr = a->lexpr; + Assert(IsA(a->rexpr, List)); + args = (List *) a->rexpr; + Assert(list_length(args) == 2); + bexpr = (Node *) linitial(args); + cexpr = (Node *) lsecond(args); + + /* + * Build the equivalent comparison expression. Make copies of + * multiply-referenced subexpressions for safety. (XXX this is really + * wrong since it results in multiple runtime evaluations of what may be + * volatile expressions ...) + * + * Ideally we would not use hard-wired operators here but instead use + * opclasses. However, mixed data types and other issues make this + * difficult: + * http://archives.postgresql.org/pgsql-hackers/2008-08/msg01142.php + */ + switch (a->kind) + { + case AEXPR_BETWEEN: + args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=", + aexpr, bexpr, + a->location), + makeSimpleA_Expr(AEXPR_OP, "<=", + copyObject(aexpr), cexpr, + a->location)); + result = (Node *) makeBoolExpr(AND_EXPR, args, a->location); + break; + case AEXPR_NOT_BETWEEN: + args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<", + aexpr, bexpr, + a->location), + makeSimpleA_Expr(AEXPR_OP, ">", + copyObject(aexpr), cexpr, + a->location)); + result = (Node *) makeBoolExpr(OR_EXPR, args, a->location); + break; + case AEXPR_BETWEEN_SYM: + args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=", + aexpr, bexpr, + a->location), + makeSimpleA_Expr(AEXPR_OP, "<=", + copyObject(aexpr), cexpr, + a->location)); + sub1 = (Node *) makeBoolExpr(AND_EXPR, args, a->location); + args = list_make2(makeSimpleA_Expr(AEXPR_OP, ">=", + copyObject(aexpr), copyObject(cexpr), + a->location), + makeSimpleA_Expr(AEXPR_OP, "<=", + copyObject(aexpr), copyObject(bexpr), + a->location)); + sub2 = (Node *) makeBoolExpr(AND_EXPR, args, a->location); + args = list_make2(sub1, sub2); + result = (Node *) makeBoolExpr(OR_EXPR, args, a->location); + break; + case AEXPR_NOT_BETWEEN_SYM: + args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<", + aexpr, bexpr, + a->location), + makeSimpleA_Expr(AEXPR_OP, ">", + copyObject(aexpr), cexpr, + a->location)); + sub1 = (Node *) makeBoolExpr(OR_EXPR, args, a->location); + args = list_make2(makeSimpleA_Expr(AEXPR_OP, "<", + copyObject(aexpr), copyObject(cexpr), + a->location), + makeSimpleA_Expr(AEXPR_OP, ">", + copyObject(aexpr), copyObject(bexpr), + a->location)); + sub2 = (Node *) makeBoolExpr(OR_EXPR, args, a->location); + args = list_make2(sub1, sub2); + result = (Node *) makeBoolExpr(AND_EXPR, args, a->location); + break; + default: + elog(ERROR, "unrecognized A_Expr kind: %d", a->kind); + result = NULL; /* keep compiler quiet */ + break; + } + + return transformExprRecurse(pstate, result); +} + +static Node * transformBoolExpr(ParseState *pstate, BoolExpr *a) { List *args = NIL; |