MyBatis联合查询语句

最新推荐文章于 2022-01-11 10:53:07 发布

asw987653

最新推荐文章于 2022-01-11 10:53:07 发布

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分类专栏： MyBatis 文章标签： java

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日志表、评论表、用户表

ReportDao.xml

<?xml version="1.0" encoding="UTF-8" ?> 
<!DOCTYPE mapper 
    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 
    "http://www.mybatis.org/dtd/mybatis-3-mapper.dtd"> 
<mapper namespace="com.xinfeijinxin.qy.dao.IreportDao"> 
<!-- 这里namespace必须是UserMapper接口的路径，不然要运行的时候要报错 “is not known to the MapperRegistry”--> 

<!-- 测试resultMap -->     
<!-- 查询日报，返回日报，日报撰写人，评论，评论人 -->
     <resultMap type="QyRb" id="myRbResult">
        <result property="gzrbid" column="gzrbid"/>
        <result property="userid" column="a_userid"/>
        <result property="rbbt" column="rbbt"/>
        <result property="rbnr" column="rbnr"/>
        <result property="tjsj" column="tjsj"/>
        
        <association property="qyUser" column="a_userid" javaType="QyUser" >
              <result property="userid" column="c_userid"/>
              <result property="xm" column="c_xm"/>
              <result property="tx" column="c_tx"/>
        </association>
         
        <collection property="qyRbpls" ofType="com.xinfeijinxin.qy.bean.QyRbpl">
           <result property="rbplid" column="rbplid"/>
           <result property="userid" column="b_userid"/>
           <result property="rbplnr" column="rbplnr"/>
           <result property="rbplsj" column="rbplsj"/>
           <association property="qyUser" column="b_userid"  javaType="QyUser">
              <result property="userid" column="d_userid"/>
              <result property="xm" column="d_xm"/>
              <result property="tx" column="d_tx"/>
           </association>
        </collection>
     </resultMap>
     
     <select id="myQueryRb" resultMap="myRbResult" parameterType="map">
        select a.gzrbid,a.rbbt,a.rbnr,a.tjsj,a.userid as a_userid,
               c.userid as c_userid,c.xm as c_xm,c.tx as c_tx,
               b.rbplid,b.userid as b_userid ,b.rbplnr,b.rbplsj,
      		   d.userid as d_userid,d.xm as d_xm,d.tx as d_tx
    	 FROM qy_rb as a 
     	 left join qy_rbpl b on a.gzrbid=b.gzrbid
    	 LEFT JOIN qy_user c ON a.userid=c.userid
     	 JOIN qy_user d      ON d.userid=b.userid

		 ORDER BY a.gzrbid
        
</select>
     
<!-- 查询日报评论数 -->  
<select id="myCountPL" resultType="int" parameterType="map">
        select count(*)
        from qy_rbpl a
        where a.gzrbid=#{gzrbid}
</select>      
</mapper>

效果图