select * from A where A.某字段 in (select distinct B.某字段 from B)lz能说细致一些么,要不回答会很广泛
select * from A where A.某字段 in (select distinct B.某字段 from B) select * from A where exists(select * from B where B.某字段=A.某字段) select A.* from A left join B on A.某字段=B.某字段 …… …… ……
select s.* from add1 s,addresses l where s.country = l.country 问题自己已解决
select * from A where exists(select * from B where B.某字段=A.某字段)
select A.* from A left join B on A.某字段=B.某字段
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问题自己已解决