mybatis （返回值）查询语句专题

素颜马尾好姑娘i 2023-09-24 19:07 44阅读 0赞

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper
            PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
            "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="com.mapper.UserMapper">
        
    
        
        
        <select id="selectTotalCount" resultType="long">
            select count(*) from user
        </select>
    
        
        <select id="getName" resultType="string">
            select name from user where id=#{id}
        </select>
    
    
        
        <select id="selectUserById" resultType="com.pojo.User">
            select * from user where id = #{id}
        </select>
    
        
        <select id="selectUserByIdToList" resultType="com.pojo.User">
            select * from user where id = #{id}
        </select>
    
        
        <select id="selectUserByIdRetMap" resultType="map">
            select * from user where id = #{id}
        </select>
    
    
        
        <select id="selectAllUsers" resultType="com.pojo.User">
            select * from user
        </select>
    
    
    
        
        <select id="selectAllUserRetListMap" resultType="map">
            select * from user
        </select>
    
        
        <select id="selectAllUserRetMap" resultType="map">
            select * from user
        </select>
    
    
        
        <resultMap id="userResultMap" type="com.pojo.User">
            
            <id property="id" column="id"/>
            
            
            <result property="name" column="name" javaType="string" jdbcType="VARCHAR"/>
            <result property="age" column="age" />
            <result property="email" column="email"/>
            <result property="sex" column="sex"/>
        </resultMap>
        
        <select id="selectAllUserByResultMap" resultMap="userResultMap">
            select * from user
        </select>
    
        
        <resultMap id="selectMap42" type="com.pojo.UserVO">
            <result property="idVO" column="id"></result>
            <collection property="userListVO" javaType="java.util.ArrayList" ofType="com.pojo.User">
                <id property="id" column="id"/>
                <result property="name" column="name" javaType="string" jdbcType="VARCHAR"/>
                <result property="age" column="age" />
                <result property="email" column="email"/>
                <result property="sex" column="sex"/>
            </collection>
        </resultMap>
        <select id="select42" resultMap="selectMap42">
            select * from user
        </select>
    
        
        <resultMap id="selectMap43" type="java.util.Map">
            <result property="name" column="name"></result>
            <collection property="userList" javaType="java.util.ArrayList" ofType="com.pojo.User">
                <id property="id" column="id"/>
                <result property="name" column="name" javaType="string" jdbcType="VARCHAR"/>
                <result property="age" column="age" />
                <result property="email" column="email"/>
                <result property="sex" column="sex"/>
            </collection>
        </resultMap>
        <select id="select43" resultMap="selectMap43">
            select id, name, age, email, sex from user
        </select>
    </mapper>

参考：

dljd - 老杜 -MyBatis讲义

[(419条消息) 【MyBatis】学习笔记06：各种查询所返回数据的数据类型\_萌狼蓝天的博客-CSDN博客][419_ _MyBatis_06_-CSDN]

(419条消息) spring boot -mybaits 的返回各种数据类型_健康平安的活着的博客-CSDN博客_mapper返回string
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            Mybatis查询返回Map＜String,List＜Object＞＞类型 - 百度文库 (baidu.com)

[419_ _MyBatis_06_-CSDN]: https://blog.csdn.net/ks2686/article/details/124031383