Mybatis-Plus一对多
Mybatis-Plus一对多及分页
xml
<?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" >
<!-- 这里填写对应的Dao文件所在的路径 -->
<mapper namespace="net.yinzhong.export.mapper.CustomsUnmixedMapper">
<!-- 通用查询映射结果 -->
<resultMap id="BaseResultMap" type="net.yinzhong.export.entity.CustomsUnmixedEntity">
<id column="id" property="id" />
<collection property="customsUnmixedExtend" ofType="net.yinzhong.export.entity.CustomsUnmixedExtendEntity" column="id" select="getCustomsUnmixedExtendList">
<result column="unmixed_id" property="unmixedId" />
<result column="gnum" property="gnum" />
</collection>
</resultMap>
<select id="getCustomsUnmixedByTid" resultMap="BaseResultMap">
select *
from yz_customs_unmixed
where tid=#{tid}
</select>
<select id="getCustomsUnmixedExtendList" resultType="net.yinzhong.export.entity.CustomsUnmixedExtendEntity">
select * FROM yz_customs_unmixed_extend WHERE unmixedId=#{unmixedId}
</select>
</mapper>
- xml上面的映射resultMap中使用collection标签来完成一对多。
- collection标签中property属性的值跟CustomsUnmixed实体类中的List属性对应,查出的多条图片的数据会映射到CustomsUnmixed这个属性中。
- collection标签中column属性值为CustomsUnmixed中的id,要根据这个id去CustomsUnmixedExtend表中查询
Mapper
List<CustomsUnmixedEntity> getCustomsUnmixedByTid(String tid); List<CustomsUnmixedExtendEntity> getCustomsUnmixedExtendList(Long unmixedId);
Server
public List<CustomsUnmixedEntity> getCustomsUnmixedByTid(String tid) {
return customsUnmixedMapper.getCustomsUnmixedByTid(tid);
}

