50分求以SQL语句－－字段的删除（在线等待，得到答案立即结贴）

[zhsu]

表a
a1 a2 a3 a4
1 2 3 4 字段a1
1 2 3 5 字段a2
2 2 3 5 字段a3
.
.
. 字段an

表b
b1 b2 b3 b4
1 2 3 8 字段b1
2 2 2 2 字段b2
.
.
. 字段bn


需要结果：删除表a里面a1=b1 and a2=b2 and a3=b3 的a、b表组合中b4=8的项。

即删除 字段a1 和字段a2

说明不清楚的地方，可以问。（在线等待，得到答案立即结贴）

[czwwh]

表a和表b是如何关联的啊？是不是表a中有表b中的字段？

[songyangk]

Delete 表a where (select a1,a2,a3,8 from 表a) t in (select b1,b2,b3,b4 from 表b)

没经过测试。

[zephyr_zhao]

你说得字段是至记录把
记录是横向的,字段时纵向的

[zjsm96441125]

delete from a where a1 in (Select b1 from b where b1 is not null) and a2 in (select b2 from b where b2 is not null) and a3 in (select b3 from b where b3 is not null)

[zephyr_zhao]

delete from a where
a1 in (select a1 from a,b where a.a1=b.b1 and a.a2=b.b2 and a.a3=b.b3 and b.b4=8)
and
a2 in (select a2 from a,b where a.a1=b.b1 and a.a2=b.b2 and a.a3=b.b3 and b.b4=8)
and
a3 in (select a3 from a,b where a.a1=b.b1 and a.a2=b.b2 and a.a3=b.b3 and b.b4=8)
amd
a4 in (select a4 from a,b where a.a1=b.b1 and a.a2=b.b2 and a.a3=b.b3 and b.b4=8)

[zjsm96441125]

上面每个 is not null 后 加上 and b4=8 (加3个）

[zhsu]

To :zephyr_zhao(zephyr)
:zjsm96441125(流星物语)

必须这么烦琐吗？三项都这么找？

[zhsu]

对，是记录。笔误，Sorry！