Question

我正在尝试从具有子table2的table1中选择项目，其中涉及第三个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：

错误：“拉”列不存在第6行：其中j.ccmasterid喜欢'W％'并拉取= 0

如果我从查询中取出“ and pull = 0 ”，它的工作原理就如同期望从table1中产生一个记录列表，其中table2中的值之和被拉出一样。

ccmasterid    pulled
W106063            0
W100553            9
W100685            1

我不知道如何基于拉为0进行选择。

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

如果关联到带有GROUP BY子句的汇总查询，则避免在外部查询中的每行中运行而不是在一次中运行的相关子查询：

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根据table2中的条件从table1中选择项目

2 个答案: