根据postgresql中的条件左连接

Question

当我执行下面的查询时，它会抛出错误说：语法错误在“as”或附近。

我们如何解决这个问题？

还有其他方法吗？

(select * from my_table1 where status='6') as a
left JOIN 
(select * from my_table1 where status='1') as b
ON (a.application_id = b.application_id)

Answer 1

通过使用子查询中的选择尝试如下所示

select a.* from (select * from my_table1 where status='6') as a
left JOIN 
(select * from my_table1 where status='1') as b
ON a.application_id = b.application_id

Answer 2

你错过了最初的select * from条款。而且，不需要子查询;你只需要小心条件放置。

select *  
from my_table1 a 
left join my_table1 b on b.status='1' and
                         b.application_id = a.application_id
where a.status='6'

Answer 3

您已从子查询中选择所有值以加入它们：

select a.* from (select * from my_table1 where status='6') as a
left JOIN 
select b.* from (select * from my_table1 where status='1') as b
ON (a.application_id = b.application_id)

Answer 4

select * from my_table1 as A 
LEFT JOIN  my_table1 as B
ON (A.application_id = A.application_id)
WHERE A.status='6' AND B.status='1'