树形结构的处理

SELECT
	T1.id 
FROM
	(
		SELECT
			@ids AS _ids,
			( SELECT @ids := GROUP_CONCAT( id ) FROM wis_organization WHERE FIND_IN_SET( pid, @ids ) ) AS cids 
		FROM
			wis_organization,
			( SELECT @ids := 67 ) b 
		WHERE
			@ids IS NOT NULL  
	) ID, wis_organization T1 
WHERE
	FIND_IN_SET( T1.id, ID._ids );