A表:a1(key),a2(key),a3(key),a4,a5
B表:b1(key),b2(key),b3(key),b4,b5
在两个表left join的时候,想要做到A表和B表的主键的值是一样的话,不显示:
a1=b1,a2=b2,a3=b3的话,
那么显示结果是:
a1,a2,a3,a4,a5
, , ,b4,b5请问,怎么写这个SQL呀?谢谢~~
B表:b1(key),b2(key),b3(key),b4,b5
在两个表left join的时候,想要做到A表和B表的主键的值是一样的话,不显示:
a1=b1,a2=b2,a3=b3的话,
那么显示结果是:
a1,a2,a3,a4,a5
, , ,b4,b5请问,怎么写这个SQL呀?谢谢~~
select distinct(a.a1),distinct(a.a2),distinct(a.a3),a.a4,b.b4,b.b5 from A a left join B b on a.a1 = b.b1 and a.a2 = b.b2 and a.a3 = b.b3 where a.a1 = 'XXXX' order by a.a4 ASCis it right?
waiting for your reply.
thanks a lot.
from a left join b on a1=b1,a2=b2,a3=b3
where b1 is null or b2 is null or b3 is null
我要的结果也不是这个。
------------------------------------------------
A表:a1(key),a2(key),a3(key),a4,a5
B表:b1(key),b2(key),b3(key),b4,b5
A表数据:1,2,3,4,5
B表数据:1,2,3,6,7最后结果:
1,2,3,4,5
, , ,6,7
from a left join b on a1=b1,a2=b2,a3=b3 这不就行了么!