mysql中delete from where子查询的限定引见【MySQL教程】,mysql

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1、运用mysql举行delete from操纵时，若子查询的 FROM 字句和更新/删除对象运用统一张表，会涌现毛病。（相干引荐：MySQL教程）

mysql> DELETE FROM 'tab' where id in (select min(id) from tag GROUP BY field1,field2 HAVING COUNT(id)>1);
error: You can't specify target table 'tab' for update in FROM clause.(不能为FROM子句中的更新指定目的表'tab')

针对“统一张表”这个限定，多半情况下都能够经由过程多加一层select 别号表来变通处理，像如许

DELETE FROM 'tab' where id in
(
    select id from 
    (
        select max(id) from 'tab' GROUP BY field1,field2 HAVING COUNT(id)>1
    ) ids
);

2.delete from table... 这个中table不能运用别号

• mysql> delete from table a where a.id in (1,2);(语法毛病)

• mysql> select a.* from table a where a.id in (1,2);(实行胜利)

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