resultMap
<?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"> <!-- namespace的名字需要跟接口的类名一致 --> <mapper namespace="cn.bdqn.dao.UserMapper"> <!-- 当数据库中的字段信息与对象的属性不一致时需要通过resultMap来映射 --> <resultMap type="User" id="seachUserResult"> <result property="id" column="id"/> <result property="userCode" column="userCode"/> <result property="userName" column="userName"/> <result property="roleId" column="roleId"/> <result property="roleName" column="roleName"/> </resultMap> <select id="count" resultType="int"> select count(1) from user </select> <insert id="add" parameterType="User"> insert into user (userCode,userName,userPassword) values (#{userCode},#{userName},#{userPassword}) </insert> <update id="update" parameterType="User"> update user set userCode=#{userCode},userName=#{userName}, userPassword=#{userPassword} where id=#{id} </update> <delete id="delete" parameterType="User"> delete from user where id=#{id} </delete> <select id="getUserList" resultType="User"> select * from user </select> <select id="getUserListByRoleId" parameterType="Role" resultMap="seachUserResult"> select u.*,r.roleName as roleName from user u,role r where u.roleId = r.id and u.roleId = #{id} </select> </mapper>