例:
select a.* from a,b,c
left join d
on d.A1 = c.A1
left join e
on e.A1 = a.A1
下面的
left join e
on e.A1 = a.A1
会出错,请问要怎么才能实现这功能呢?
分数虽然不多,比较急,请达人指教!
select a.* from a,b,c
left join d
on d.A1 = c.A1
left join e
on e.A1 = a.A1
下面的
left join e
on e.A1 = a.A1
会出错,请问要怎么才能实现这功能呢?
分数虽然不多,比较急,请达人指教!
from a left join d
on a.A1=d.A1
left join e
on e.A1 = d.A1
from (a,b,c) left join d on d.A1 = c.A1
left join e on e.A1 = a.A1
left join d
on d.A1 = c.A1
left join e
on e.A1 = a.A1
下面的
left join e
on e.A1 = a.A1这个写法不对...按 @ACMAIN_CHM 可以的对于左连接正确用法,推荐文章 剖析:MySQL的左连接、右连接、等值连接异同