Mysql 通过父节点ID获取所有子节点数据函数

BEGIN
DECLARE sTemp text;
DECLARE sTempChd text;

SET sTemp = '$';
SET sTempChd =cast(rootId as CHAR);

WHILE sTempChd is not null DO
SET sTemp = concat(sTemp,',',sTempChd);
SELECT group_concat(deptId) INTO sTempChd FROM ch_class where FIND_IN_SET(deptParId,sTempChd)>0;
END WHILE;
RETURN sTemp;
END

select * from ch_class where FIND_IN_SET(deptId,getParLst((SELECT MIN(id) from ch_class where kdgId = 机构ID))) GROUP BY deptParId;