Sql server 如何在联接表的分组数据中使用子查询对两列求和

我有一个疑问：

SELECT COUNT(*) as Avalied
FROM PY_LeaveTransactionMasterTAB as lm
JOIN PY_LeaveTransactionSubsidaryTAB as ls 
ON lm.LV_TransMasterId = ls.LV_TransMasterId
WHERE lm.SystemCode = 'faheem123' AND lm.EmployeeCode = '0014' AND lm.Status ='Approved'
Group by lm.Status

上述查询返回：

Availed
-------
   3

还有一个问题：

SELECT PY_Leave + CY_Leave as Openning 
FROM PY_LeaveOpeningTAB 
WHERE SystemCode = 'faheem123' and EmployeeCode = '0014'

此查询返回：

Openning
--------
   25
   23
   30

我想结合以上两个查询得到以下结果：

Openning   Availed
--------   --------
   25         3
   23         0
   30         0

---

我如何实现上述结果？谢谢：）

我不认为您希望一行显示“3”，而另一行显示“0”。你可以这样做：

SELECT (PY_Leave + CY_Leave) as Openning,
       (CASE WHEN PY_Leave + CY_Leave = 25 THEN x.Avalied ELSE 0 END) as Avalied
FROM PY_LeaveOpeningTAB lo CROSS JOIN
     (SELECT COUNT(*) as Avalied
      FROM PY_LeaveTransactionMasterTAB lm JOIN
           PY_LeaveTransactionSubsidaryTAB as ls 
           ON lm.LV_TransMasterId = ls.LV_TransMasterId
      WHERE lm.SystemCode = 'faheem123' AND lm.EmployeeCode = '0014' AND
            lm.Status ='Approved'
     ) x
WHERE lo.SystemCode = 'faheem123' and lo.EmployeeCode = '0014';

---

正如我所说的，（对我来说）删除

案例并将“3”放在所有三个“匹配”行上更有意义。
您可以尝试使用CTE

 WITH CTE_preselect AS (
 SELECT EmployeeCode,PY_Leave + CY_Leave as Openning 
 FROM PY_LeaveOpeningTAB 
 WHERE SystemCode = 'faheem123' and EmployeeCode = '0014'
 )

 SELECT Openning,COUNT(*) as Avalied
 FROM PY_LeaveTransactionMasterTAB as lm
 JOIN PY_LeaveTransactionSubsidaryTAB as ls 
 ON lm.LV_TransMasterId = ls.LV_TransMasterId
 JOIN CTE_preselect ON lm.EmployeeCode = CTE_preselect.EmployeeCode
 WHERE lm.SystemCode = 'faheem123' AND lm.EmployeeCode = '0014' AND 
 lm.Status ='Approved'
 Group by Openning,lm.Status

假设可用的“属于”第一行

Select A.Opening
      ,Availed = case when A.RN=1 then B.Availed else 0 end)
 From (
        SELECT PY_Leave + CY_Leave as Openning 
              ,RN = Row_Number() over (Order by (Select NULL))
         FROM PY_LeaveOpeningTAB 
         WHERE SystemCode = 'faheem123' and EmployeeCode = '0014'
      ) A
 Cross Join (
                SELECT COUNT(*) as Avalied
                FROM PY_LeaveTransactionMasterTAB as lm
                JOIN PY_LeaveTransactionSubsidaryTAB as ls 
                ON lm.LV_TransMasterId = ls.LV_TransMasterId
                WHERE lm.SystemCode = 'faheem123' AND lm.EmployeeCode = '0014' AND lm.Status ='Approved'
                Group by lm.Status
            ) B

为什么您不希望所有三行上的
可用
都使用“3”
呢？对于
打开
值
25
的
PY_LeaveTransactionSubsidaryTAB
表中有3行计数，而对于其他行，在
PY_LeaveTransactionSubsidaryTAB
表中找不到行计数，这就是为什么我要为它们显示
0
，您的查询将始终返回可用的
0
，如果
Openning
是
25
，我想显示相应的行计数（如果找到），如果没有，则显示
0
。