0)背景:有一个表格里面有很多的人每天的工作安排,要求按月为单位查询出coefficient字段的总和,SQL如下:
SELECT name,shifts,SUM(coefficient) FROM WORK WHERE YEAR(TIME)=2020 AND MONTH(TIME)=1 AND nameID=#{nameID} GROUP BY shifts
问题:但是name
和shifts
前台可以拿到,但是coefficient
确拿不到;
解决:把SUM(coefficient)
后面加上coefficient
,SQL如下:
SELECT name,shifts,SUM(coefficient) coefficient FROM WORK WHERE YEAR(TIME)=2020 AND MONTH(TIME)=1 AND nameID=#{nameID} GROUP BY shifts