sql中insert語句內的select語句返回多行

Question

我在mysql中有以下結構化查詢。 但是它返回一個錯誤。 基本上，我想從現有表中獲取價值並插入新表中。 我嘗試了以下操作，但出現錯誤；

INSERT INTO `table1`(
    `first`,`second`,`third`) VALUES(

    (SELECT table2.timemodified FROM `xtable` AS table2,`ytable` AS table3 
        WHERE table3.id = table2.contextid),

    (SELECT table4.id FROM `ztable` AS table4,`ytable` AS table3 WHERE table4.id = table3.instanceid),

    (SELECT murs.id FROM `table5` AS murs,
    `xtable` AS table2, 
    `wtable` AS table6, 
    `ytable` AS table3, 
    `vtable` AS table7 
    WHERE murs.id = table2.userid AND table6.id = table2.roleid AND table3.id = table2.contextid AND table7.instance = table3.instanceid AND table6.id =3)
);

我測試過，但錯誤是： #1242 - Subquery returns more than 1 row 。 問題是我從insert內的select查詢中獲得的記錄不止一個。 我該如何消除這種錯誤。

Answer 1

總查詢如下所示。 在這里，請用您要選擇的列名稱替換*！

INSERT INTO table1(first,second,third)

-- replace * with columns name first,second,third
select * from (
-- START YOU'RE select query
(SELECT table2.timemodified FROM `xtable` AS table2,`ytable` AS table3 
        WHERE table3.id = table2.contextid),

    (SELECT table4.id FROM `ztable` AS table4,`ytable` AS table3 WHERE table4.id = table3.instanceid),

    (SELECT murs.id FROM `table5` AS murs,
    `xtable` AS table2, 
    `wtable` AS table6, 
    `ytable` AS table3, 
    `vtable` AS table7 
    WHERE murs.id = table2.userid AND table6.id = table2.roleid AND table3.id = table2.contextid AND table7.instance = table3.instanceid AND table6.id =3)
-- END YOU'RE select query
)

我將您的select語句移到了子查詢中，因此您可以利用子查詢的總結果來發揮自己的優勢。