MyBatis - 两种查询树形数据（最多三级结构）

@Data
@JsonInclude(value = JsonInclude.Include.NON_EMPTY)
public class OrgTree implements Serializable {
 
    private String id;
 
    private String label;
 
    private List<OrgTree> children;
 
}

<resultMap type="com.dto.OrgTree" id="BaseResultMap">
        <id column="id" property="id"/>
        <result column="label" property="label"/>
        <collection property="children" ofType="com.dto.OrgTree">
            <id column="id2" property="id"/>
            <result column="label2" property="label"/>
            <collection property="children" ofType="com.dto.OrgTree">
                <id column="id3" property="id"/>
                <result column="label3" property="label"/>
            </collection>
        </collection>
    </resultMap>
    
<select id="getOrgTree" resultMap="BaseResultMap">
        select
            m1.org_code as id,
            m1.org_name as label,
            m2.org_code as id2,
            m2.org_name as label2,
            m3.org_code as id3,
            m3.org_name as label3
        from org_table m1,org_table m2,org_table m3
        where
			m1.org_code=m2.parent_org_code
			and
		    m2.org_code=m3.parent_org_code
 
        <!--可以根据不同用户的级别查询当前用户的组织-->
        <if test="firstCode != '' and firstCode != null ">
            and m1.org_code=#{firstCode}
        </if>
        <if test="secondCode  != '' and secondCode != null ">
            and m2.org_code=#{secondCode}
        </if>
        <if test="thirdCode != '' and thirdCode != null ">
            and m3.org_code=#{thirdCode}
        </if>
 
 
	  order by id,id2,id3
    </select>

MyBatis - 两种查询树形数据的方法详解（嵌套结果集、递归查询）

参考连接