关于 sql 查询和删除....请教！

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This topic created in 2930 days ago, the information mentioned may be changed or developed.

select A.ID from A left join B on A.ID=B.ID where B.ID is null

1.我用以上语句搜出了和 B 表未关联的 A.ID

2.请问我该如何写 sql 才能直接删除这些 A.ID ，既一条语句删除查出来未关联的 ID

SQL

删除

语句

关联

8 replies • 2018-07-20 22:43:44 +08:00

cnmllll

Jul 20, 2018

delete from A.ID where A.ID not not in (select A.ID from A left join B on A.ID=B.ID where B.ID is null)
这样可以么

cnmllll

Jul 20, 2018

delete from A where A.ID not not in (select A.ID from A left join B on A.ID=B.ID where B.ID is null)
这个

jintianfengda

Jul 20, 2018

DELETE
a
FROM
a
LEFT JOIN
b
ON
a.ID = b.ID
WHERE
b.id is null

cnmllll

Jul 20, 2018

delete from A where A.ID in (select A.ID from A left join B on A.ID=B.ID where B.ID is null) 这个终极版

akira

Jul 20, 2018

这个 sql 和 select id from A where id is null 有啥区别

lrh3321

Jul 20, 2018

@akira 表 A 中的行在表 B 中不一定有对应的行，他要删的就是这些无用的行。

akira

Jul 20, 2018

@lrh3321 嗯呐，审题不仔细 >"<

iwiki

Jul 20, 2018

delete from a where not exists (select 1 from b where a.id=b.id)