mysql 按时间段分组

SELECT
        foodid,nums,sum(quantity)
FROM (
    SELECT
        
        CASE
                WHEN weighedtime >= concat_ws(" ",DATE_FORMAT(weighedtime,'%Y-%m-%d'),"00:00:01")
                AND weighedtime < concat_ws(" ",DATE_FORMAT(weighedtime,'%Y-%m-%d'),"08:00:00") THEN
                    1
                WHEN weighedtime >= concat_ws(" ",DATE_FORMAT(weighedtime,'%Y-%m-%d'),"08:00:01")
                AND weighedtime < concat_ws(" ",DATE_FORMAT(weighedtime,'%Y-%m-%d'),"12:00:00") THEN
                    2
                WHEN weighedtime >= concat_ws(" ",DATE_FORMAT(weighedtime,'%Y-%m-%d'),"12:00:01")
                AND weighedtime < concat_ws(" ",DATE_FORMAT(weighedtime,'%Y-%m-%d'),"19:00:00") THEN
                    3
                WHEN weighedtime >= concat_ws(" ",DATE_FORMAT(weighedtime,'%Y-%m-%d'),"19:00:01")
                AND weighedtime < concat_ws(" ",DATE_FORMAT(weighedtime,'%Y-%m-%d'),"23:00:00") THEN
                    4
        END as nums,
        quantity,
        foodid,
        DATE_FORMAT(weighedtime,'%Y-%m-%d') as dtime
    FROM
        tab t where 1=1 order by t.weighedtime
 
) t group by nums,foodid limit 0,10