一、聚合函数查询
1.配置实体类
package com.demo;
public class demo {
//接收集合函数
private String count;
private String sum;
}
2.配置MyBatis映射
.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//ibatis.apache.org//DTD Mapper 3.0//EN" "http://ibatis.apache.org/dtd/ibatis-3-mapper.dtd"> <mapper namespace="com.demo.demoDao"> <resultMap id="demo" type="com.demo.demo"> <result column="count" property="count"/> <result column="sum" property="sum"/> </resultMap> <select id="getSum" resultMap="demo"> SELECT count(*) as count, sum(*) as sum FROM table_name </select> </mapper>
.java
package com.demo;
public interface demoDao{
public demo getSum(demo demo);
}
3.业务层
package com.demo;
@Service
public class demoService{
@Autowired
private demoDao demoDao;
public void getSum(Demo demo){
Demo result = demoDao.getsum(demo);
String sum = result.getsum;
String count = result.getCount();
}
}
原文:https://www.cnblogs.com/zhang20190701/p/12181101.html