update B set name=(select name from A where B.A_id=A.id),content=(select
content from A where where B.A_id=A.id)
where exists (select 'x' from A where A.id = B.A_id)
content from A where where B.A_id=A.id)
where exists (select 'x' from A where A.id = B.A_id)
解决方案 »
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