两张表查询

显示全部楼层 · 2009-3-2 15:37:48

select a from table1where b in (select b from table2 )
select a from table1where b in (select b from table3)

两张表A字段内容有重复，如何将A字段内容对比
不是去重``是要找到那些内容是重复的```

千问 · 2009-3-2 15:37:48

SQL2005用except/intersect比较比较存在重复select a from table1 where b in (select b from table2 ) intersectselect a from table1 where b in (select b from table3)orselectafrom table1where b in(select b from(select distinct b from table2 union all select distinct b from table3)t group by b having count(*)>1)...

千问 · 2009-3-2 15:37:48

----a在两个查询都存在用下面的select a from (select a from table1 where b in (select b from table2)) c, (select a from table1 where b in (select b from table3)) d where c.a=d.a---...