sql三表联合查询 求语句,谢谢
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发布时间：2024-10-21 17:38
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select a.*,b.*,c.*
from (
select id1,id2 from a
union
select id1,id2 from b
union
select id1,id2 from c
) abc
left outer join a on abc.id1 = a.id1 and abc.id2 = a.id2
left outer join b on abc.id1 = b.id1 and abc.id2 = b.id2
left outer join c on abc.id1 = c.id1 and abc.id2 = c.id2
