Mybatis处理多个Sum()结果返回null

Question

如下面代码所示，sql可以正常返回求和信息，mybatis为什么会回null ，是不是我的mapper映射有问题？？？

• dao

• sql语句,正常返回求和

  

• Mappr 文件

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Answer 1

查询的结果集与result的column名对不上，可以在sum(...)添加别名。mapper中的sql改为：SELECT id, court_name, depart_name, SUM(info_1) info_1, SUM(info_2) info_2, SUM(info_3) info_3, SUM(info_4) info_4, SUM(info_5) info_5, SUM(info_6) info_6, SUM(info_7) info_7, SUM(info_8) info_8, SUM(info_9) info_9, SUM(info_10) info_10, SUM(info_11) info_11, SUM(info_12) info_12, s_month, s_year FROM caselist_info <where> <if test="courtName != null"> and court_name = #{courtName} </if> </where> GROUP BY court_name, depart_name