Mybatis返回Map集合数据

entity—— Easyuser

package com.example.test1.entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Easyuser {
    private int id;
    private String  username;
    private String password;
    private String email;
    private String role;
    private boolean state;
}

mapper——EasyMapper

package com.example.test1.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.test1.entity.Easyuser;
import org.apache.ibatis.annotations.MapKey;
import org.springframework.stereotype.Repository;

import java.util.List;
import java.util.Map;

@Repository
public interface EasyUserMapper extends BaseMapper<Easyuser> {
    //返回单条Map  @MapKey("id")用于设置Map中的key
    @MapKey("id")
    Map<Integer, Easyuser> selectByMap(Integer id);

    //返回多条Map
    @MapKey("id") @MapKey("id")用于设置Map中的key
    Map<Integer, Easyuser> searchMap(List<Integer> list);
}

mapper.xml——EasyMapper.xml

<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.test1.mapper.EasyUserMapper">

    <resultMap id="BaseResultMap" type="com.example.test1.entity.Easyuser">
       <result property="id" column="id"></result>
        <result property="username" column="username"></result>
    </resultMap>
<!--BaseResultMap来映射我们Map集合中的value值，存的是对象类型-->
    <select id="selectByMap" resultMap="BaseResultMap" resultType="java.util.HashMap">
        select  * from easyuser where id=#{id}
    </select>

    <select id="searchMap"  resultMap="BaseResultMap" resultType="java.util.HashMap" >
        select * from easyuser where id in
        <foreach collection="list" item="id" index="index"  open="(" close=")" separator=",">
            #{id}
        </foreach>
    </select>
</mapper>

测试Test

package com.example.test1;

import com.example.test1.entity.Easyuser;
import com.example.test1.mapper.EasyUserMapper;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Set;

@SpringBootTest
class Test1ApplicationTests {
    @Autowired
    EasyUserMapper easyUserMapper;
    @Test
    void contextLoads() {

        System.out.println("***********单条map******************");
        Map<Integer, Easyuser> map = easyUserMapper.selectByMap(1);
        System.out.println(map);
        System.out.println("***********多条map******************");
        List<Integer> list= Arrays.asList(1,2,3);
        Map<Integer, Easyuser> maps = easyUserMapper.searchMap(list);
        System.out.println(maps);
    }
}

输出结果

***********单条map******************
2021-04-14 19:25:29.340  INFO 13692 --- [           main] com.alibaba.druid.pool.DruidDataSource   : {dataSource-1} inited
{1=Easyuser(id=1, username=admin, password=123456, email=[email protected], role=超级管理员, state=true)}
***********多条map******************
{1=Easyuser(id=1, username=admin, password=123456, email=[email protected], role=超级管理员, state=true), 
2=Easyuser(id=2, username=naughty, password=888888, email=[email protected], role=普通管理员, state=false), 
3=Easyuser(id=3, username=flysky01, password=987654, email=[email protected], role=普通用户, state=true)}