Mybatis集合映射 有重名怎么办

<?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.base.modules.visitor.dao.VisitorRecordInfoDao">

	<!--有用的Mapper -->
    <resultMap type="com.base.modules.visitor.entity.VisitorRecordInfoEntity" id="visitorRecordInfoMap">
        <result property="id" column="id"/>
        <result property="visitorRecordNo" column="visitor_record_no"/>
        <result property="visitorType" column="visitor_type"/>
        <result property="addressId" column="address_id"/>
        <result property="reasonCode" column="reason_code"/>
        <result property="hasFollower" column="has_follower"/>
        <result property="hasCar" column="has_car"/>
        <result property="applicantJobNum" column="applicant_job_num"/>
        <result property="applicantName" column="applicant_name"/>
        <result property="applicantPhone" column="applicant_phone"/>
        <result property="receiverJobNum" column="receiver_job_num"/>
        <result property="assginee" column="assginee"/>
        <result property="examineCode" column="examine_code"/>
        <result property="examineValue" column="examine_value"/>
        <result property="startTime" column="start_time"/>
        <result property="endTime" column="end_time"/>
        <result property="inviteMethod" column="invite_method"/>
        <result property="remarks" column="remarks"/>
        <result property="status" column="status"/>
        <result property="revision" column="revision"/>
        <result property="createdBy" column="created_by"/>
        <result property="createdTime" column="created_time"/>
        <result property="updatedBy" column="updated_by"/>
        <result property="updatedTime" column="updated_time"/>
        <result property="todayNum" column="today_num"/>
        <collection property="userList" ofType="com.base.modules.visitor.entity.VisitorUserEntity">
            <result property="id" column="id"/>
            <result property="jobNum" column="job_num"/>
            <result property="name" column="name"/>
            <result property="gender" column="gender"/>
            <result property="dept" column="dept"/>
            <result property="company" column="company"/>
            <result property="phone" column="phone"/>
            <result property="wxId" column="wx_id"/>
            <result property="cardCount" column="card_count"/>
            <result property="carNo" column="car_no"/>
            <result property="qrCode" column="qr_code"/>
            <result property="revision" column="revision"/>
            <result property="createdBy" column="created_by"/>
            <result property="createdTime" column="created_time"/>
            <result property="updatedBy" column="updated_by"/>
            <result property="updatedTime" column="updated_time"/>
        </collection>

    </resultMap>




    <select id="getMaxSerialNum"  resultType="Integer" >
        select IFNULL(max(today_num),0)  from visitor_record_info where  DATE_FORMAT(created_time, '%Y-%m-%d') =CURDATE()
    </select>


    <select id="selectMyStartList"  parameterType="map" resultMap="visitorRecordInfoMap" >
        SELECT
        i.visitor_record_no AS visitorRecordNo,
        i.visitor_type AS visitorType,
        ddd.`name` AS visitorTypeName,
        i.reason_code AS reasonCode,
        dd.`name` AS reasonCodeName,
        i.examine_code AS examineCode,
        d.`name` AS examineCodeName,
        i.applicant_job_num applicantJobNum,
        i.applicant_name applicantName,
        i.applicant_phone applicantPhone,
        i.receiver_job_num receiverJobNum,
        e.name_zh receiverName,
        e.mobile receiverphone,
        i.assginee AS assginee,
        i.address_id addressId,
        oc.address addressName,
        i.start_time startTime,
        i.end_time endTime,
        rurr.job_num AS mainUserJobNum,
        uu.`name` AS mainUserName,
        rur.id AS userList.vrurId,
        rur.visitor_record_no AS userList.visitorRecordNo,
        rur.job_num AS userList.jobNum,
        rur.visitor_status AS userList.visitorStatus,
        rur.is_follower AS userList.isFollower,
        rur.parent_job_num AS userList.parentJobNum,
        rur.auth_job_num AS userList.assgineeJobNum,
        rur.type AS userList.visitorType,
        rur. STATUS AS userList.status,
        u.`name` AS userList.name,
        u.company AS userList.company,
        u.job_num AS userList.jobNum,
        u.phone AS userList.phone,
        u.wx_id AS userList.wxId,
        u.car_no AS userList.carNo,
        f.photo_url AS userList.photoUrl,
        rur.is_sign_in AS userList.isSignIn
        FROM
        visitor_record_info i
        LEFT JOIN visitor_dist ddd ON ddd. CODE = i.visitor_type
        LEFT JOIN visitor_dist dd ON dd. CODE = i.reason_code
        LEFT JOIN visitor_dist d ON d. CODE = i.examine_code
        LEFT JOIN oa_company oc ON oc.id = i.address_id
        LEFT JOIN ehr_staff e ON e.hr_id = i.receiver_job_num
        LEFT JOIN visitor_record_user_relation rurr ON i.visitor_record_no = rurr.visitor_record_no
        AND (
        rurr.parent_job_num IS NULL
        OR rurr.parent_job_num = ''
        )
        LEFT JOIN visitor_record_user_relation rur ON i.visitor_record_no = rur.visitor_record_no
        INNER JOIN visitor_user u ON u.job_num = rur.job_num
        INNER JOIN visitor_face f ON f.job_num = u.job_num
        INNER JOIN visitor_user uu ON uu.job_num = rurr.job_num
        WHERE 1=1
        and i.applicant_job_num = #{jobNum}

        <if test="visitorName != null and visitorName != ''">
            AND o.visitorName = #{visitorName}
        </if>

        <if test="reasonName != null and reasonName != ''">
            AND o.reasonName = #{reasonName}
        </if>


    </select>

重名解决：
本来是想在sql里写userList.isSignIn这种东西指定，但肯定报错。依稀记得是传参时#{}可以用.语法指定吧。

观察了一下Mybatis玩法，它应该无法知道我真实数据库里列是啥样，那么这个column应该是sql的结果而已。所以，我把column改了不就是另一处的起别名吗~（sql起别名的话，表属性名不好配合它改：真实的表的真实列名和实体类是肯定不好改的。那就该Mapper这里的结果的列名吧，故，这里的column可以看作“形式列名”）
当Mapper column与实体类属性名取一样，sql里别名也叫这个，那么，result用Mapper（resultMap）就相当于直接result用实体类接收（resultType）一样。此时，用resultMap纯属于脱裤子放屁——多此一举，闲得蛋疼，纯自找麻烦，纯傻批。

总结：

sql那取别名，如果结果类型是对象，那么，取的别名与对象属性名（取别名时的思路目标就是取在这）一致即可自动映射，比较舒服又快；如果结果类型用Mapper，那么，就是与Mapper的column一致（那么，取别名时的思路目标就是取在这了，算是个中转站，但也提高了适用性、复用性、扩展性，可以不动表和实体类），然后column再与对象属性名一一对应即可自动映射，就是配起来累，费眼神。

<?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.base.modules.visitor.dao.VisitorRecordInfoDao">

	<!--有用的Mapper -->
    <resultMap type="com.base.modules.visitor.entity.VisitorRecordInfoEntity" id="visitorRecordInfoMap">
        <result property="id" column="id"/>
        <result property="visitorRecordNo" column="visitor_record_no"/>
        <result property="visitorType" column="visitor_type"/>
        <result property="addressId" column="address_id"/>
        <result property="reasonCode" column="reason_code"/>
        <result property="hasFollower" column="has_follower"/>
        <result property="hasCar" column="has_car"/>
        <result property="applicantJobNum" column="applicant_job_num"/>
        <result property="applicantName" column="applicant_name"/>
        <result property="applicantPhone" column="applicant_phone"/>
        <result property="receiverJobNum" column="receiver_job_num"/>
        <result property="assginee" column="assginee"/>
        <result property="examineCode" column="examine_code"/>
        <result property="examineValue" column="examine_value"/>
        <result property="startTime" column="start_time"/>
        <result property="endTime" column="end_time"/>
        <result property="inviteMethod" column="invite_method"/>
        <result property="remarks" column="remarks"/>
        <result property="status" column="status"/>
        <result property="revision" column="revision"/>
        <result property="createdBy" column="created_by"/>
        <result property="createdTime" column="created_time"/>
        <result property="updatedBy" column="updated_by"/>
        <result property="updatedTime" column="updated_time"/>
        <result property="todayNum" column="today_num"/>
        <collection property="userList" ofType="com.base.modules.visitor.entity.VisitorUserEntity">
            <result property="vrurId" column="userList_vrurId"/>
            <result property="visitorRecordNo" column="userList_visitorRecordNo"/>
            <result property="jobNum" column="userList_jobNum"/>
            <result property="visitorStatus" column="userList_visitorStatus"/>
            <result property="isFollower" column="userList_isFollower"/>
            <result property="parentJobNum" column="userList_parentJobNum"/>
            <result property="assgineeJobNum" column="userList_assgineeJobNum"/>
            <result property="visitorType" column="userList_visitorType"/>
            <result property="status" column="userList_status"/>
            <result property="name" column="userList_name"/>
            <result property="company" column="userList_company"/>
            <result property="phone" column="userList_phone"/>
            <result property="wxId" column="userList_wxId"/>
            <result property="carNo" column="userList_carNo"/>
            <result property="photoUrl" column="userList_photoUrl"/>
            <result property="isSignIn" column="userList_isSignIn"/>
            <result property="cardCount" column="card_count"/>
            <result property="gender" column="gender"/>
            <result property="dept" column="dept"/>
            <result property="qrCode" column="qr_code"/>
            <result property="revision" column="revision"/>
            <result property="createdBy" column="created_by"/>
            <result property="createdTime" column="created_time"/>
            <result property="updatedBy" column="updated_by"/>
            <result property="updatedTime" column="updated_time"/>
        </collection>

    </resultMap>

还不够，得再改（编码习惯和“入参或结果类型是个对象时”不一样了，没那么自动舒服了）-------
吐了，用Mapper就是麻烦，仔细对应xml，配得累，眼花，你就失去了“入参或结果类型是个对象时”自动映射的爽了。而得事无巨细的在Mapper一个一个配（结果column和对象属性名）

<!--有用的Mapper -->
    <resultMap type="com.cowain.base.modules.visitor.entity.VisitorRecordInfoEntity" id="visitorRecordInfoMap">
        <result property="id" column="id"/>
        <result property="visitorRecordNo" column="visitor_record_no"/>
        <result property="visitorTypeName" column="visitorTypeName"/>
        <result property="reasonCode" column="reasonCode"/>
        <result property="reasonCodeName" column="reasonCodeName"/>
        <result property="examineCode" column="examineCode"/>
        <result property="examineCodeName" column="examineCodeName"/>
        <result property="applicantJobNum" column="applicant_job_num"/>
        <result property="applicantName" column="applicant_name"/>
        <result property="applicantPhone" column="applicant_phone"/>
        <result property="receiverJobNum" column="receiver_job_num"/>
        <result property="receiverName" column="receiverName"/>
        <result property="receiverphone" column="receiverphone"/>
        <result property="assginee" column="assginee"/>
        <result property="visitorType" column="visitor_type"/>
        <result property="addressId" column="address_id"/>
        <result property="addressName" column="addressName"/>
        <result property="mainUserJobNum" column="mainUserJobNum"/>
        <result property="mainUserName" column="mainUserName"/>
        <result property="reasonCode" column="reason_code"/>
        <result property="hasFollower" column="has_follower"/>
        <result property="hasCar" column="has_car"/>
        <result property="examineCode" column="examine_code"/>
        <result property="examineValue" column="examine_value"/>
        <result property="startTime" column="start_time"/>
        <result property="endTime" column="end_time"/>
        <result property="inviteMethod" column="invite_method"/>
        <result property="remarks" column="remarks"/>
        <result property="status" column="status"/>
        <result property="revision" column="revision"/>
        <result property="createdBy" column="created_by"/>
        <result property="createdTime" column="created_time"/>
        <result property="updatedBy" column="updated_by"/>
        <result property="updatedTime" column="updated_time"/>
        <result property="todayNum" column="today_num"/>
        <collection property="userList" ofType="com.cowain.base.modules.visitor.entity.VisitorUserEntity">
            <result property="vrurId" column="userList_vrurId"/>
            <result property="visitorRecordNo" column="userList_visitorRecordNo"/>
            <result property="jobNum" column="userList_jobNum"/>
            <result property="visitorStatus" column="userList_visitorStatus"/>
            <result property="isFollower" column="userList_isFollower"/>
            <result property="parentJobNum" column="userList_parentJobNum"/>
            <result property="assgineeJobNum" column="userList_assgineeJobNum"/>
            <result property="visitorType" column="userList_visitorType"/>
            <result property="status" column="userList_status"/>
            <result property="name" column="userList_name"/>
            <result property="company" column="userList_company"/>
            <result property="phone" column="userList_phone"/>
            <result property="wxId" column="userList_wxId"/>
            <result property="carNo" column="userList_carNo"/>
            <result property="photoUrl" column="userList_photoUrl"/>
            <result property="isSignIn" column="userList_isSignIn"/>
            <result property="cardCount" column="card_count"/>
            <result property="gender" column="gender"/>
            <result property="dept" column="dept"/>
            <result property="qrCode" column="qr_code"/>
            <result property="revision" column="revision"/>
            <result property="createdBy" column="created_by"/>
            <result property="createdTime" column="created_time"/>
            <result property="updatedBy" column="updated_by"/>
            <result property="updatedTime" column="updated_time"/>
        </collection>

    </resultMap>

从结果来讲，Mybatis总体上还是很智能自动好用~

多重嵌套：依样画葫芦，即可



但Mybatis < collection>（xml配置时）有一个bug：
这个photoUrls其实是userList每一个元素（user）的属性，而且映射结果（Mybatis把查询结果是根据集合主键userList_id去聚合的）确实是映射到了每一个用户的照片集上。但是，在配嵌套< collection>时（第三层），我只给user对象配photoUrls属性，竟然冒红，而是我得给订单配photoUrls（虽然映射完了这里是null），它竟然找这个，那我嵌套写法（< collection>套< collection>）宛如未嵌（平行）似的，这个逻辑上面属实bug了（ Mybatis 写时不智能（结果映射是智能的，据说根据的是子属性的主键id，然而我第三层嵌套时又没配照片主键id column…-_-||不懂），它只对着第一层，即使它被我嵌套了）。

其他(三层以上嵌套)做法：

（(Me:整麻烦了，java基本类型和String没property就不写就行了)）mybatis 对象 List List属性 映射

ResultMap collection多层嵌套使用
mybatis collection多层嵌套 （三层嵌套）

Mapper如果配了三层嵌套collection但结果集里却没有第三层会有毒【感觉跟那bug的味道差不多，你嵌套了，但是Mybatis它是以第一层对象的属性去看待它（第三层集合映射）的，去找它的，而且可能是基本数据类型或string，有些小坑吧】（所有，非树状结果的话却有三层以上嵌套且存在嵌套层是基本数据类型或string为元素的集合映射，接收的结果Type慎用Mapper!）：Mapper嵌套写了，要当心。如果查的sql返回不存在这个第三层嵌套的字段（解决：这是就不要用Mapper接收，就用实体类简单接收就好了。简单解决。很奇葩），那么竟然要报错。。