Postgresql SQL Select 表 1 中的项目基于表 2 中的条件

Question

我正在尝试 select table1 中的项目，其中有一个子 table2 涉及第三个 table3。

Select j.ccmasterid, 
(Select sum(i.ccmatpullqty) From table2 i 
 Where i.ccmasterid = j.ccmasterid)  pulled
 from table1 j
INNER JOIN table3 s on j.ccstatus = s.sysstatusid and s.ccopenjob=false
where j.ccmasterid LIKE 'W%' and pulled = 0

这会产生一个错误：

ERROR: column "pulled" does not exist LINE 6: where j.ccmasterid LIKE 'W%' and pulled = 0

如果我从查询中取出“and pulled = 0”，它的工作方式就像人们期望的那样从 table1 中生成一个记录列表，其中的值的总和表 2 拉。

ccmasterid    pulled
W106063            0
W100553            9
W100685            1

我想不通的是如何 select 基于拉为 0。

Answer 1

将此查询更改为子查询，并将 WHERE 条件移动到外部查询：

SELECT * FROM (
   Select j.ccmasterid, 
   (Select sum(i.ccmatpullqty) From table2 i 
    Where i.ccmasterid = j.ccmasterid)  pulled
    from table1 j
   INNER JOIN table3 s on j.ccstatus = s.sysstatusid and s.ccopenjob=false
   where j.ccmasterid LIKE 'W%'
) x
WHERE  pulled = 0

Answer 2

避免在外部查询中针对 every 行而不是 once 运行的相关子查询，如果加入 [=12] 的聚合查询=] 子句：

SELECT j.ccmasterid
FROM table1 j
INNER JOIN table3 s 
    ON j.ccstatus = s.sysstatusid AND s.ccopenjob = false
INNER JOIN
   (SELECT i.ccmasterid, SUM(i.ccmatpullqty) AS pulled
    FROM table2 i 
    GROUP BY i.ccmasterid
   ) AS agg
    ON agg.ccmasterid = j.ccmasterid
WHERE j.ccmasterid LIKE 'W%' AND agg.pulled = 0

甚至使用 CTE

WITH agg AS
    (SELECT i.ccmasterid, SUM(i.ccmatpullqty) AS pulled
     FROM table2 i 
     GROUP BY i.ccmasterid)

SELECT j.ccmasterid
FROM table1 j
INNER JOIN table3 s 
    ON j.ccstatus = s.sysstatusid AND s.ccopenjob = false
INNER JOIN agg
    ON agg.ccmasterid = j.ccmasterid
WHERE j.ccmasterid LIKE 'W%' AND agg.pulled = 0

Postgresql SQL Select 表 1 中的项目基于表 2 中的条件

Postgresql SQL Select items from table1 based on a condition from table2

sql

postgresql

conditional