mabaties常用结果返回类型总结

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public interface UserMapper {//mappper映射之単个参数User findUserById(long id);//mapper多参数传参List<User> findUserBysome(String aa);List<User> findUserBysome2(String aa);User findUserBysome3(String aa);User findUserBysome4(String aa);List<Map> findUserBysome5(String aa);Map  findUserById1(long id);

<?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.itheima.mybatis.mapper.UserMapper"><insert  id="insertUser" parameterType="com.itheima.mybatis.po.User">     insert into user (u_id,u_name,u_age) value(#{u_id},#{u_name},#{age})</insert><select id="findUserById" parameterType="long" resultType="User">   select * from user where u_id = #{id}</select><resultMap id="userResule" type="User">   <id property="u_id" column="u_id"></id>   <result property="u_name" column="u_name"></result>   <result property="age" column="u_age"></result></resultMap><select id="findUserBysome" resultType="User">   select * from user where u_name like concat ('%',#{aa},'%')</select><select id="findUserBysome2" resultMap="userResule">   select * from user where u_name like concat ('%',#{aa},'%')</select><select id="findUserBysome3" resultMap="userResule">   select * from user where u_name like concat ('%',#{aa},'%')</select>    <select id="findUserBysome4" resultMap="userResule">   select * from user where u_name like concat ('%',#{aa},'%')</select><select id="findUserBysome5" resultType="java.util.HashMap" >   select * from user where u_name like concat ('%',#{aa},'%')</select>    <select id="findUserById1" parameterType="long" resultType="java.util.HashMap">   select * from user where u_id = #{id}</select></mapper>

如上所示是一些常用的mabatis结果返回类型:

resutlType resultMap都可以返回单个的对象或是对象的集合,而java.util.HashMap可以返回图或是图的集合，对象，对象集合，图，图集合是最常用的结果返回类型

当提供的返回类型属性是resultType时，MyBatis会将Map里面的键值对取出赋给resultType所指定的对象对应的属性。所以其实MyBatis的每一个查询映射的返回类型都是ResultMap，只是当提供的返回类型属性是resultType的时
候，MyBatis对自动的给把对应的值赋给resultType所指定对象的属性。

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