diff options
Diffstat (limited to 'contrib/postgres_fdw/deparse.c')
| -rw-r--r-- | contrib/postgres_fdw/deparse.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/contrib/postgres_fdw/deparse.c b/contrib/postgres_fdw/deparse.c index 8f09cd51ca8..dd25699d83f 100644 --- a/contrib/postgres_fdw/deparse.c +++ b/contrib/postgres_fdw/deparse.c @@ -1806,10 +1806,27 @@ deparseNullTest(NullTest *node, deparse_expr_cxt *context) appendStringInfoChar(buf, '('); deparseExpr(node->arg, context); - if (node->nulltesttype == IS_NULL) - appendStringInfoString(buf, " IS NULL)"); + + /* + * 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 (node->argisrow || !type_is_rowtype(exprType((Node *) node->arg))) + { + if (node->nulltesttype == IS_NULL) + appendStringInfoString(buf, " IS NULL)"); + else + appendStringInfoString(buf, " IS NOT NULL)"); + } else - appendStringInfoString(buf, " IS NOT NULL)"); + { + if (node->nulltesttype == IS_NULL) + appendStringInfoString(buf, " IS NOT DISTINCT FROM NULL)"); + else + appendStringInfoString(buf, " IS DISTINCT FROM NULL)"); + } } /* |