MySQL删除重复记录且保留一条
MySQL大约 522 字DELETE from user2 WHERE id not in (SELECT id from user2 GROUP BY `name`);
报错:
[Err] 1093 - You can't specify target table 'user2' for update in FROM clause
原因:
更新数据时使用了查询,而查询的数据又做更新的条件,MySQL不支持这种方式
DELETE from user2 WHERE id not in (
SELECT * from (
SELECT id from user2 GROUP BY `name`
)
);
报错:
[Err] 1248 - Every derived table must have its own alias
每个派生表都必须有自己的别名
derived 派生
DELETE from user2 WHERE id not in (
SELECT * from (
SELECT id from user2 GROUP BY `name`
) as id
);
ok
阅读 349 · 发布于 2019-04-07
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