sql中插入语句中的select语句返回多行 [英] select statement inside insert statement in sql returns multiple rows

问题描述

我在 mysql 中有以下结构化查询.但它返回一个错误.基本上，我想从现有表中获取价值并插入新表.我尝试了以下操作，但出现错误；

I have a following structured query in mysql. But its returning a error. Basically, I want to get value from existing table and instert into new table. I tried the following, but got error;

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)
);

我测试过，但错误是:#1242 - 子查询返回超过 1 行.问题是我从 insert 内的 select 查询中获得了多个记录.我怎样才能消除这样的错误.

I tested but the error is : #1242 - Subquery returns more than 1 row. The problem is I am getting more than single record from the select query inside insert. How can I remove such error.

推荐答案

整个查询如下所示.将 * 替换为要选择的列名！

the total query looks something like below. where you have so replace the * with column names you want to select!

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
)

我将您的选择语句移到了子查询中，以便您可以利用子查询的总结果对您有利.

I moved you're select statements into a subquery so you can use the total result of the subquerys to you're advantage.

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