[enhance](variant) throw exception when field type is not supported i…

…n cast elimation (apache#40388)

be/src/olap/tablet_reader.cpp

@@ -30,6 +30,7 @@
 
 #include "common/compiler_util.h" // IWYU pragma: keep
 #include "common/config.h"
+#include "common/exception.h"
 #include "common/logging.h"
 #include "common/status.h"
 #include "exprs/bitmapfilter_predicate.h"
@@ -273,6 +274,10 @@ TabletColumn TabletReader::materialize_column(const TabletColumn& orig) {
     TabletColumn column_with_cast_type = orig;
     auto cast_type = _reader_context.target_cast_type_for_variants.at(orig.name());
     FieldType filed_type = TabletColumn::get_field_type_by_type(cast_type.type);
+    if (filed_type == FieldType::OLAP_FIELD_TYPE_UNKNOWN) {
+        throw doris::Exception(ErrorCode::INTERNAL_ERROR, "Invalid type for variant column: {}",
+                               cast_type.type);
+    }
     column_with_cast_type.set_type(filed_type);
     return column_with_cast_type;
 }

regression-test/suites/variant_p0/load.groovy

@@ -426,6 +426,11 @@ suite("regression_test_variant", "p0"){
             exception("errCode = 2, detailMessage = Variant type should not be used in key")
         }
 
+        test {
+            sql """select * from ghdata where cast(v['actor']['url'] as ipv4) = '127.0.0.1'""" 
+            exception("Invalid type for variant column: 36")
+        }
+
     } finally {
         // reset flags
     }