解决MyBatis 多表联合查询,字段重复的问题

时间:2025-04-27 14:37:58
ZSJC1 和ZSJC2 是一对多关系
@Data
@TableName("zsj_c1")
public class ZSJC1 {
    private int id;
    private String name;

    @TableField(exist = false)
    private List<ZSJC2> zsjc2s;
}
@Data
@TableName("zsj_c2")
public class ZSJC2 {

    private int id;

    private String name;

    private String type;

    private int c1Id;
}

ZSJC1 实体类id,name与ZSJC1实体类id,name字段一样,ZSJC1 与ZSJC1关系是一对多关联,如果在mybatis不使用别名的话,mybatis是识别不了的,查询出来的结果是混乱的

使用别名的查询如下 :

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-////DTD Mapper 3.0//EN" "/dtd/">
<mapper namespace="">

    <resultMap  type=".ZSJC1">
        <id column="id" property="id"/>
        <result column="name" property="name"/>
        <collection property="zsjc2s" ofType=".ZSJC2">
            <id column="cid"  property="id" />
            <result column="cname" property="name" />
            <result column="type" property="type"/>
            <result column="c1Id" property="c1Id" />
        </collection>
    </resultMap>

    <select  resultMap="BaseMap">
          SELECT ,, AS cid, AS cname,,b.c1_id AS c1Id
          FROM  zsj_c1 a
          LEFT JOIN zsj_c2 b
          ON =b.c1_id
          WHERE =1
    </select>

</mapper>