diff options
Diffstat (limited to 'src/backend/utils/adt/ruleutils.c')
| -rw-r--r-- | src/backend/utils/adt/ruleutils.c | 46 |
1 files changed, 36 insertions, 10 deletions
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 8af9b9a4a9d..ad3efa8e9c0 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -5732,17 +5732,43 @@ get_rule_expr(Node *node, deparse_context *context, if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, '('); get_rule_expr_paren((Node *) ntest->arg, context, true, node); - switch (ntest->nulltesttype) + + /* + * For scalar inputs, we prefer to print as IS [NOT] NULL, + * which is shorter and traditional. If it's a rowtype input + * but we're applying a scalar test, must print IS [NOT] + * DISTINCT FROM NULL to be semantically correct. + */ + if (ntest->argisrow || + !type_is_rowtype(exprType((Node *) ntest->arg))) { - case IS_NULL: - appendStringInfo(buf, " IS NULL"); - break; - case IS_NOT_NULL: - appendStringInfo(buf, " IS NOT NULL"); - break; - default: - elog(ERROR, "unrecognized nulltesttype: %d", - (int) ntest->nulltesttype); + switch (ntest->nulltesttype) + { + case IS_NULL: + appendStringInfo(buf, " IS NULL"); + break; + case IS_NOT_NULL: + appendStringInfo(buf, " IS NOT NULL"); + break; + default: + elog(ERROR, "unrecognized nulltesttype: %d", + (int) ntest->nulltesttype); + } + } + else + { + switch (ntest->nulltesttype) + { + case IS_NULL: + appendStringInfo(buf, " IS NOT DISTINCT FROM NULL"); + break; + case IS_NOT_NULL: + appendStringInfo(buf, " IS DISTINCT FROM NULL"); + break; + default: + elog(ERROR, "unrecognized nulltesttype: %d", + (int) ntest->nulltesttype); + } } if (!PRETTY_PAREN(context)) appendStringInfoChar(buf, ')'); |