Insert into Select query返回重复的行

Question

INSERT INTO INT_TBL_2 (product_id, UR_id, lang_code, country_code, named_obj_class,     
                       named_obj_phonemes, total_phonemes, total_named_objects)
SELECT product_id, UR_id, lang_code, country_code, named_obj_class, 
       SUM(named_obj_phonemes), SUM(total_phonemes), SUM(total_named_objects) 
FROM INT_TBL_1 
WHERE named_obj_class = "city" 
GROUP BY product_id, UR_id, lang_code, country_code, named_obj_class

我的查询会在Oracle开发人员手动运行时生成正确的结果。但是，当通过C ++代码调用时，相同的查询会产生重复5000次的结果。

请注意，表INT_TBL_2在插入之前始终为空（新创建）。