業務場景：需要記入訪客的訪問情況，但不能重復記入 ***** 可以插入前進行判斷要插入的數據是否存在業務代碼如下 ： INSERT INTO t_topic_vistor(user_id,topic_code) SELECT '218', 'XQ33019920170811142528217' FROM DUAL WHERE NOT EXISTS(SELECT * FROM t_topic_vistor WHERE user_id = 218 and topic_code='XQ33019920170811142528217') ***** 語法如下： test_sql="INSERT INTO table(field1, field2, fieldn) SELECT 'field1', 'field2', 'fieldn' FROM DUAL WHERE NOT EXISTS(SELECT field FROM table WHERE field = ?)" 然后直接執行這條語句就可以 如python里 cursor.execute(test_sql) *****