每个派生表都必须有自己的别名mysql和临时表

有人能帮忙吗，因为我不知道这个错误消息来自哪里：

每个派生表都必须有自己的别名

在我看来，我在所有表中都添加了别名

SELECT ccdnormal.*
FROM card_call_detail AS ccdnormal
JOIN (

    SELECT ccd1.DB_CALL_ID
    FROM card_call_detail_tmp1 AS ccd1
    JOIN card_call_detail_tmp2 AS ccd2 ON ccd1.card_number = ccd2.card_number
    WHERE ccd1.start_time <> ccd2.start_time
      AND ccd1.end_time > ccd2.start_time
      AND ccd1.DB_CALL_ID <> ccd2.DB_CALL_ID
      AND ccd2.start_time BETWEEN ccd1.start_time AND ccd1.end_time

    UNION ALL

    SELECT ccd4.DB_CALL_ID
    FROM card_call_detail_tmp3 AS ccd3
    JOIN card_call_detail_tmp4 AS ccd4 ON ccd3.card_number = ccd4.card_number
    WHERE ccd3.start_time <> ccd4.start_time
      AND ccd3.end_time > ccd4.start_time
      AND ccd3.DB_CALL_ID <> ccd4.DB_CALL_ID
      AND ccd4.start_time BETWEEN ccd3.start_time AND ccd3.end_time )

) AS CCDOUTPUT ON CCDOUTPUT.DB_CALL_ID = ccdnormal.DB_CALL_ID

---

随机提示：在联合选择周围添加：选择。。。UNION ALL SELECT…如图所示，由于括号不平衡，出现语法错误。@eggyal，这是什么意思？biziclop他的回答对我没有帮助…@user1496811:你打开一个括号，关闭两个括号。你完全正确！我自己没有看到：S。非常感谢你！