Mybatis查询结果ResultMap的继承-蒲公英云

Mybatis查询结果ResultMap的继承

需求：在查询用户表的同时，关联角色表查出角色名称(假设每个用户只有一个角色)

//用户类
public class User {
    private String id;
    private String name;
    private String roleId;
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getRoleId() {
        return roleId;
    }
    public void setRoleId(String roleId) {
        this.roleId = roleId;
    }
}
//角色类
public class Role {
    private String id;
    private String name;
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}
//接收查询结果的用户类
public class UserView extends User{
    private String roleName;
    public String getRoleName() {
        return roleName;
    }
    public void setRoleName(String roleName) {
        this.roleName= roleName;
    }
}

XML文件

<resultMap id="BaseResultMap" type="User" >
    <id column="id" property="id" jdbcType="VARCHAR" />
    <result column="name" property="name" jdbcType="VARCHAR" />
    <result column="role_id" property="roleId" jdbcType="VARCHAR" />
  </resultMap>
 <resultMap id="ViewMap" type="UserView" extends="BaseResultMap">
    <result column="role_name" property="roleName" jdbcType="VARCHAR" />
 </resultMap>
 <select id="queryList" resultMap="ViewMap" parameterType="UserView">
    select
        u.id,
        u.name,
        u.role_id,
        r.name as role_name
    from user u
    left join role r
    on u.role_id = r.id 
</select>