CREATE FUNCTION `vendor_area_child_ids`(rootId INT)
 RETURNS varchar(1000)
BEGIN 
       DECLARE pTemp VARCHAR(1000);  
       DECLARE cTemp VARCHAR(1000);  
      
       SET pTemp = ‘$‘;  
       SET cTemp =cast(rootId as CHAR);  
       
       WHILE cTemp is not null DO  
         SET pTemp = concat(pTemp,‘,‘,cTemp); 
         SELECT group_concat(id) INTO cTemp FROM pd_vendor_area WHERE FIND_IN_SET(parent_id,cTemp)>0; 
       END WHILE;  
       RETURN pTemp;  
END;