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); }