diff options
Diffstat (limited to 'src/backend/parser/parse_expr.c')
| -rw-r--r-- | src/backend/parser/parse_expr.c | 37 |
1 files changed, 35 insertions, 2 deletions
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c index 34ac17868b5..1c1c86aa3e9 100644 --- a/src/backend/parser/parse_expr.c +++ b/src/backend/parser/parse_expr.c @@ -4617,6 +4617,40 @@ coerceJsonExprOutput(ParseState *pstate, JsonExpr *jsexpr) } /* + * Recursively checks if the given expression, or its sub-node in some cases, + * is valid for using as an ON ERROR / ON EMPTY DEFAULT expression. + */ +static bool +ValidJsonBehaviorDefaultExpr(Node *expr, void *context) +{ + if (expr == NULL) + return false; + + switch (nodeTag(expr)) + { + /* Acceptable expression nodes */ + case T_Const: + case T_FuncExpr: + case T_OpExpr: + return true; + + /* Acceptable iff arg of the following nodes is one of the above */ + case T_CoerceViaIO: + case T_CoerceToDomain: + case T_ArrayCoerceExpr: + case T_ConvertRowtypeExpr: + case T_RelabelType: + case T_CollateExpr: + return expression_tree_walker(expr, ValidJsonBehaviorDefaultExpr, + context); + default: + break; + } + + return false; +} + +/* * Transform a JSON BEHAVIOR clause. */ static JsonBehavior * @@ -4636,8 +4670,7 @@ transformJsonBehavior(ParseState *pstate, JsonBehavior *behavior, if (btype == JSON_BEHAVIOR_DEFAULT) { expr = transformExprRecurse(pstate, behavior->expr); - if (!IsA(expr, Const) && !IsA(expr, FuncExpr) && - !IsA(expr, OpExpr)) + if (!ValidJsonBehaviorDefaultExpr(expr, NULL)) ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH), errmsg("can only specify a constant, non-aggregate function, or operator expression for DEFAULT"), |