2.1.1 一对多查询

在网络上有着两个一对多查询方式，但是只有一个是能用的，使用ResultMap方式进行一对多查询，

其中在Mapper.xml中如下配置：

<?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.acompe.security.mapper.UserMapper">
    <select id="findUserByUsername" resultMap="user" parameterType="String">
        SELECT a.id,a.username,a.`password`,a.is_enable,a.create_time,a.update_time, p.url
        FROM user_account a
        INNER JOIN user_account_role ar
        ON a.id = ar.user_account_id
        INNER JOIN user_role_permission rp
        ON ar.user_role_id =  rp.user_role_id
        INNER JOIN user_permission p
        ON rp.user_permission_id = p.id
        WHERE a.id = 1;
    </select>
    <resultMap id="user" type="com.acompe.security.model.po.User">
        <id column="id" property="id"/>
        <result column="username" property="username"/>
        <result column="password" property="password"/>
        <result column="is_enable" property="isEnable"/>
        <result column="create_time" property="createTime"/>
        <result column="update_time" property="updateTime"/>
        <collection property="authorities" ofType="org.springframework.security.core.authority.SimpleGrantedAuthority">
            <result column="url" property="role"/>
        </collection>
    </resultMap>
</mapper>