[英]sql deleat from one table with compare data another table both don't have PK,FK relation
我有两个表名 tblstu 和 tblmark tblstu 有 3 条记录,分别在 tblmark 中有 pk(1,2,3) 相同的记录,但 tblmark 有 3 条额外的记录,在 tblstu 中找不到,我可以从 tblmark 那里删除不匹配的记录吗?两个表中 pk 和 fk 没有关系
ANSI SQL answer: ANSI SQL 答案:
delete from tblmark where id not IN (select id from tblstu)
If tblstu.id is nullable, adjust to:如果 tblstu.id 可为空,则调整为:
delete from tblmark where id not IN (select id from tblstu where id is not null)
DELETE FROM tblmark
WHERE NOT EXISTS (SELECT 1
FROM tblstu
WHERE tblmark.PK = tblstu.PK)
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