Mybatis的多表操作2

//role角色表
    private Integer roleId;
    private String roleName;
    private String roleDesc;
    //多对多的关系映射 一个角色可以赋予多个用户
    private List<User> users;

//用户表实体
        private Integer id;
        private String username;
        private String address;
        private String sex;
        private Date birthday;
//多对多的关系映射，一个用户可以具备多个角色
        private List<Role> roles;

	<mapper namespace="com.rpf.dao.UserDao">
    <!--定义User的ResuleMap-->
    <resultMap id="userMap" type="user">
        <id property="id" column="id"></id>
        <result property="username" column="username"></result>
        <result property="address" column="address"></result>
        <result property="sex" column="sex"></result>
        <result property="birthday" column="birthday"></result>
   <collection property="roles" ofType="role">
       <id property="roleId" column="rid"></id>
       <result property="roleName" column="role_name"></result>
       <result property="roleDesc" column="role_desc"></result>
   </collection>
    </resultMap>
    <!--配置查询所有-->
    <select id="findAll" resultMap="userMap"><!--resultType="com.rpf.domain.User"-->
        select u.*,r.id as rid,r.role_name,r.role_desc from user u
        left outer join user_role ur on u.id =ur.uid
        left outer join role r on r.id=ur.rid
    </select>

</mapper>

	当我们查询角色时，可以同时得到角色的所赋予的用户信息

  <mapper namespace="com.rpf.dao.RoleDao">
    <!--查询所有-->
    <resultMap id="roleMap" type="Role">
        <id property="roleId" column="rid"></id>
        <result property="roleName" column="role_name"></result>
        <result property="roleDesc" column="role_desc"></result>
        <collection property="users" ofType="user">
            <id column="id" property="id"></id>
            <result column="username" property="username"></result>
            <result column="address" property="address"></result>
            <result column="sex" property="sex"></result>
            <result column="birthday" property="birthday"></result>
        </collection>
    </resultMap>
   <select id="findAll" resultMap="roleMap">
              select u.*,r.id as rid,r.role_name,r.role_desc from role r left outer join user_role ur on r.id =ur.rid
              left outer join user u on u.id=ur.uid
   </select>

 @Test
    public void findAll(){
        List<User> users=userDao.findAll();
        for (User user:users){
            System.out.println(user);
            System.out.println(user.getRoles());
        }
    }