ok

app/services/sql_validator_service.py

@@ -64,6 +64,9 @@ _READ_ONLY_TYPES: frozenset[QueryType] = frozenset(
 
 _AST_TYPE_MAP: list[tuple[type[exp.Expression], QueryType]] = [
     (exp.Select, QueryType.SELECT),
+    (exp.Union, QueryType.SELECT),
+    (exp.Intersect, QueryType.SELECT),
+    (exp.Except, QueryType.SELECT),
     (exp.Insert, QueryType.INSERT),
     (exp.Update, QueryType.UPDATE),
     (exp.Delete, QueryType.DELETE),