我有这个Employee_Detail表，看起来像下面的
ID| EMP_NO| EMP_NAME| YEARMONTH| CURR_MTH_PAY_AMT| TOTAL_CURR_MTH_PAY_AMT| CURR_MTH_DED_AMT| TOTAL_CURR_MTH_DED_AMT
1| 1 | 'Alan' | 201712 | 100 | NULL | 50 | NULL
2| 1 | 'Alan' | 201712 | 200 | NULL | 70 | NULL
3| 1 | 'Alan' | 201712 | 300 | NULL | 80 | NULL
4| 1 | 'Alan' | 201801 | 1000 | NULL | 500 | NULL
5| 1 | 'Alan' | 201801 | 2000 | NULL | 700 | NULL
6| 1 | 'Alan' | 201801 | 3000 | NULL | 800 | NULL
7| 1 | 'Alan' | 201801 | 4000 | NULL | 700 | NULL
8| 2 | 'Bob' | 201712 | 400 | NULL | 50 | NULL
9| 2 | 'Bob' | 201712 | 500 | NULL | 60 | NULL
10| 2 | 'Bob' | 201712 | 600 | NULL | 70 | NULL
11| 2 | 'Bob' | 201802 | 700 | NULL | 70 | NULL
12| 2 | 'Bob' | 201802 | 800 | NULL | 80 | NULL
13| 2 | 'Bob' | 201802 | 900 | NULL | 90 | NULL
14| 2 | 'Bob' | 201802 | 900 | NULL | 90 | NULL
我正在尝试为每个TOTAL_CURR_MTH_PAY_AMT as SUM(CURR_MTH_PAY_AMT)的每位员工更新TOTAL_CURR_MTH_DED_AMT as SUM(CURR_MTH_DED_AMT)和yearmonth，以便我的表格如下所示。
ID| EMP_NO| EMP_NAME| YEARMONTH| CURR_MTH_PAY_AMT| TOTAL_CURR_MTH_PAY_AMT| CURR_MTH_DED_AMT| TOTAL_CURR_MTH_DED_AMT
1| 1 | 'Alan' | 201712 | 100 | 600 | 50 | 200
2| 1 | 'Alan' | 201712 | 200 | 600 | 70 | 200
3| 1 | 'Alan' | 201712 | 300 | 600 | 80 | 200
4| 1 | 'Alan' | 201801 | 1000 |10000 | 500 | 2700
5| 1 | 'Alan' | 201801 | 2000 |10000 | 700 | 2700
6| 1 | 'Alan' | 201801 | 3000 |10000 | 800 | 2700
7| 1 | 'Alan' | 201801 | 4000 |10000 | 700 | 2700
8| 2 | 'Bob' | 201712 | 400 | 1500 | 50 | 180
9| 2 | 'Bob' | 201712 | 500 | 1500 | 60 | 180
10| 2 | 'Bob' | 201712 | 600 | 1500 | 70 | 180
11| 2 | 'Bob' | 201802 | 700 | 3300 | 70 | 330
12| 2 | 'Bob' | 201802 | 800 | 3300 | 80 | 330
13| 2 | 'Bob' | 201802 | 900 | 3300 | 90 | 330
14| 2 | 'Bob' | 201802 | 900 | 3300 | 90 | 330
我尝试在Mysql上使用此查询
update Employee_Detail set TOTAL_CURR_MTH_PAY_AMT = SUM(CURR_MTH_PAY_AMT) , TOTAL_CURR_MTH_DED_AMT = SUM(CURR_MTH_DED_AMT)
group by YYYYMM, EMP_NO;
但它给了我这个错误
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'group by YEARMONTH, EMP_NO'.
我无法在更新时使用group by子句。任何帮助将不胜感激。
答案 0 :(得分：1)
您无法将update用于update Employee_Detail
join (
select EMP_NO, YEARMONTH, sum(CURR_MTH_PAY_AMT) TOTAL_CURR_MTH_PAY_AMT, SUM(CURR_MTH_DED_AMT) TOTAL_CURR_MTH_DED_AMT
from Employee_Detail
group by EMP_NO, YEARMONTH
) t on Employee_Detail.EMP_NO = t.EMP_NO AND Employee_Detail.YEARMONTH = T.YEARMONTH
set Employee_Detail.TOTAL_CURR_MTH_PAY_AMT = t.TOTAL_CURR_MTH_PAY_AMT,
Employee_Detail.TOTAL_CURR_MTH_DED_AMT = t.TOTAL_CURR_MTH_DED_AMT
，相反，您可以尝试这样做：
CURR_MTH_PAY_AMT子查询将为每个组提取总计CURR_MTH_DED_AMT和总计join，然后Employee_Detail in memory来更新每条记录。