mysql 联合不工作

Question

嗨，我正在尝试合并两个表。

我的 id 只存在于左表中，我的 id 只存在于右表中。我想要一张包含所有 id 的表。我尝试过:

select * from temp_hours as a
    left outer join temp_orders as o on a.proj_id = o.proj_id
union
select * from temp_hours as a
    right outer join temp_orders as o on a.proj_id = o.proj_id

但我收到错误:

Can't reopen table: 'a'

我有什么想法可以做到这一点吗？服务器版本:5.0.51a-24+lenny4(Debian)

Answer 1

按照建议添加括号或更改缩写...

select * from temp_hours as a
    left outer join temp_orders as ao on a.proj_id = ao.proj_id
union
select * from temp_hours as b
    right outer join temp_orders as bo on b.proj_id = bo.proj_id