mysql - 如何将字段传递给 join 语句中的另一个 sql 短语

Question

我正在尝试执行此操作，并且希望第二个 sql 语句中的“a”成为第一个查询中的“a”。

Select 
    a1,b,c,d,e,f,g,h,a2,b2 
from
    (Select 
        a as a1,b,c,d,e,f,g,h 
    from 
        `table1` 
    inner join 
        `table2` 
    where 
        table1.a=table2.a and b=0)z 
join
    (Select 
        a2,b2
    from
        `table3`
    where
        b2=1 and a=a2
    group by b2)x
group by a

这导致“a”未知。

我尝试对第二个 sql 语句中的“a”执行这些操作:

z.a，a1，z.a1

请指导我。

Answer 1

在公共(public)列上进行内连接

Select 
    a1,b,c,d,e,f,g,h,a2,b2 
from
    (Select 
        a as a1,b,c,d,e,f,g,h 
    from 
        `table1` 
    inner join 
        `table2` 
    where 
        table1.a=table2.a and b=0)z 
Inner join
    (Select 
        a2,b2
    from
        `table3`
    where
        b2=1 
    group by b2)x
On z.a=x.a2
group by a1