抱歉，不确定此问题的正确标题是什么。 需要帮助＆amp;关于这个问题的建议：
我有两张桌子：
--table_sum
SELECT Outlet + '-' + Department as Outlet,
COUNT (*) as Headcount,
SUM (Basic + Allowance + Overtime) - Deduction as Amount
FROM table_sum WHERE
year = 2016 AND month = 4 AND
(Basic + Allowance + Overtime)- Deduction > 0
GROUP BY Outlet, Department
Emp no Outlet Department Basic Allowance Overtime Deduction
101 OLET1 DET1 $2,000.00 $250.00 $30.00 $10.00
102 OLET2 DET2 $1,800.00 $100.00 $50.00 $10.00
103 OLET1 DET1 $2,500.00 $250.00 $20.00 $-
104 OLET2 DET1 $3,500.00 $100.00 $- $-
--table_details
SELECT SUM (Amount)
FROM Table_details
WHERE year = 2016 AND month = 4
AND Code = 'OTA'
Emp No Outlet Department Code Code Description Amount
101 OLET1 DET1 BSC Basic $2,000.00
101 OLET1 DET1 CRA Car Allowance $100.00
101 OLET1 DET1 OTA Other Allowance $150.00
101 OLET1 DET1 OTP Normal Day Overtime $30.00
101 OLET1 DET1 UFD Uniform Deduction $10.00
102 OLET2 DET2 BSC Basic $1,800.00
102 OLET2 DET2 CRA Car Allowance $100.00
102 OLET2 DET2 OTP Normal Day Overtime $50.00
102 OLET2 DET2 UFD Uniform Deduction $10.00
103 OLET1 DET1 BSC Basic $2,500.00
103 OLET1 DET1 CRA Car Allowance $100.00
103 OLET1 DET1 OTA Other Allowance $150.00
103 OLET1 DET1 OTP Normal Day Overtime $20.00
104 OLET2 DET1 BSC Basic $3,500.00
104 OLET2 DET1 CRA Car Allowance $100.00
正如你在table_sum中看到的那样，所有的免税额已经在＆＃34; Allowance＆＃34;中得到了总结。柱。我的计划不包括扣除津贴的计算中的一些津贴 - 这就是table_details的来源：
SELECT Outlet + '-' + Department as Outlet,
COUNT (*) as Headcount,
SUM (Basic + Allowance + Overtime) - Deduction -
(SELECT SUM (z.Amount) FROM Table_details z
WHERE z.Outlet=Table_sum.Outlet AND z.Outlet=Table_sum
AND z.Department=Table_sum.Department
AND z.year = 2016 AND z.month = 4
AND z.Code = 'OTA') as Amount --deduct OTA Allowance Amount
FROM table_sum
WHERE year = 2016 AND month = 4
AND (Basic + Allowance + Overtime)- Deduction > 0
GROUP BY Outlet, Department
结果：
Outlet Headcount Amount
OLET1-DET1 2 $4,740
OLET2-DET1 1 NULL
OLET2-DET2 1 NULL
我意识到在＃34; OLET2-DET1＆＃34; ＆安培; ＆＃34; OLET2-DET2＆＃34;没有＆＃39; OTA＆＃39;津贴。因此，结果变为NULL。对此有何建议？
谢谢！
解决：
SELECT Outlet + '-' + Department as Outlet,
COUNT (*) as Headcount,
SUM (Basic + Allowance + Overtime) - Deduction -
ISNULL((SELECT SUM (z.Amount) FROM Table_details z
WHERE z.Outlet=Table_sum.Outlet AND z.Outlet=Table_sum
AND z.Department=Table_sum.Department
AND z.year = 2016 AND z.month = 4
AND z.Code = 'OTA'),0) as Amount --deduct OTA Allowance Amount
FROM table_sum
WHERE year = 2016 AND month = 4
AND (Basic + Allowance + Overtime)- Deduction > 0
GROUP BY Outlet, Department
答案 0 :(得分：1)
将子查询包装在ISNULL语句中：
SELECT Outlet + '-' + Department as Outlet,
COUNT (*) as Headcount,
SUM (Basic + Allowance + Overtime) - Deduction -
ISNULL ( (SELECT SUM (z.Amount) FROM Table_details z
WHERE z.Outlet=Table_sum.Outlet AND z.Outlet=Table_sum
AND z.Department=Table_sum.Department
AND z.year = 2016 AND z.month = 4
AND z.Code = 'OTA'), 0 ) as Amount --deduct OTA Allowance Amount
FROM table_sum
WHERE year = 2016 AND month = 4
AND (Basic + Allowance + Overtime)- Deduction > 0
GROUP BY Outlet, Department
答案 1 :(得分：1)
我尊重Kyle Hale给出的答案，但ISNULL应该是字段级而不是查询级别，如下所示
SELECT Outlet + '-' + Department as Outlet,
COUNT (*) as Headcount,
SUM (Basic + Allowance + Overtime) - Deduction -
(SELECT SUM (ISNULL (z.Amount, 0)) FROM Table_details z
WHERE z.Outlet=Table_sum.Outlet AND z.Outlet=Table_sum
AND z.Department=Table_sum.Department
AND z.year = 2016 AND z.month = 4
AND z.Code = 'OTA') as Amount --deduct OTA Allowance Amount
FROM table_sum
WHERE year = 2016 AND month = 4
AND (Basic + Allowance + Overtime)- Deduction > 0
GROUP BY Outlet, Department
答案 2 :(得分：1)
当表之间的公共字段更快时，您必须始终使用连接查询。
这是2方法，也阅读评论中的说明。
--Approach 1 : simple join
SELECT Outlet + '-' + Department as Outlet,
COUNT (*) as Headcount,
SUM (Basic + Allowance + Overtime) - Deduction -
ISNULL ( SUM (z.Amount) as Amount --deduct OTA Allowance Amount
FROM table_sum ts --give alias name to identiy easily
--add left outer, so if null value found, then main table data is not mismatch
Left outer JOIN Table_details z on z.Outlet=Table_sum.Outlet and z.year = ts.year and z.month = ts.month and z.code = 'OTA'
WHERE ts.year = 2016 AND month = 4
AND (ts.Basic + ts.Allowance + ts.Overtime)- ts.Deduction > 0
GROUP BY ts.Outlet, ts.Department
--Approach 2 : Use CTE and join
;with cte
as
(
SELECT z.Outlet, SUM (z.Amount)
FROM Table_details z
WHERE z.year = 2016 AND z.month = 4
AND z.Code = 'OTA'
Group By z.Outlet
)
SELECT Outlet + '-' + Department as Outlet,
COUNT (*) as Headcount,
SUM (Basic + Allowance + Overtime) - Deduction -
ISNULL ( SUM (z.Amount) as Amount --deduct OTA Allowance Amount
FROM table_sum ts --give alias name to identiy easily
Left outer JOIN cte z on z.Outlet=Table_sum.Outlet --add left outer, so if null value found, then main table data is not mismatch
WHERE ts.year = 2016 AND month = 4
AND (ts.Basic + ts.Allowance + ts.Overtime)- ts.Deduction > 0
GROUP BY ts.Outlet, ts.Department