SELECT departmentId,AVG(salary) AS avg_salary FROM t_employee GROUP BY department_id; @TestpublicvoidselectByQueryWrapper9(){ QueryWrapper<Employee> queryWrapper=newQueryWrapper();//QueryWrapper<Employee> queryWrapper2=Wrappers.<Employee>query();queryWrapper .select("department_id","AVG(salary) AS avg...
public void selectByQueryWrapper7(){ QueryWrapper<Employee> queryWrapper=new QueryWrapper(); // QueryWrapper<Employee> queryWrapper2=Wrappers.<Employee>query(); queryWrapper.select("id","name").gt("salary",3500).like("name","小"); List<Employee> employeeList = employeeMapper.selectList(queryWrappe...
Spring Boot 整合 Mybatis-Plus 2019-12-14 18:09 −1.Spring 整合 Mybatis-Plus a.链接:https://www.cnblogs.com/vettel0329/p/11990721.html 2.后端搭建: a.在数据库创建 tb_user 用户表 -- 用户表 CREATE TABL... 晨M风 0 804 关于mybatis-plus 和 mybatis-plus-boot-starter 异同点分析 ...
1.返回特定的几个字段 select(字段…) 2.排除某几个字段 select(entiyClass,predicate判断) 3.分组聚合函数 select(“聚合函数”) 搭配service的.listMaps方法,将返回的数据封装到map中 避免了多余字段的返回 实例 实例一: public AjaxResult listAll(ProjectBuild projectBuild) { //只返回了id和name两个字段 L...