mysql 樹形查詢函數
BEGIN
DECLARE res VARCHAR(1000);
DECLARE child VARCHAR(1000);
SET res='$';
SET child=id;
while child IS NOT NULL DO
set res=CONCAT(res,',',child);
SELECT GROUP_CONCAT(jgdm) into child FROM dwb WHERE FIND_IN_SET(ssdw,child)>0;
END WHILE;
RETURN res;
END