mysql查询过去24小时内每小时数据量的方法(精确到分钟)

SET @i=-1;
SELECT DATE_SUB( NOW(),INTERVAL ( (@i:=@i+1) ) HOUR ) AS 'time' 
FROM  mysql.help_category 
WHERE @i<23

SET @i=-1;
SELECT DATE_SUB( NOW(), INTERVAL((@i:=@i+1)) HOUR) AS 'time' 
FROM 
(SELECT *  FROM 
	(SELECT '1' AS a UNION SELECT '2' UNION SELECT '3' UNION SELECT '4'   ) AS a
 	JOIN 
	( SELECT  '1' UNION  '2' UNION SELECT '3' UNION SELECT '4' UNION SELECT '5' UNION SELECT '6' ) AS b
 ) AS c 
 WHERE @i<23

SELECT DATE_FORMAT(DATE_SUB( create_time,INTERVAL MINUTE(NOW())-60 MINUTE ) ,'%Y-%m-%d %H') AS date, count(*) AS num 
FROM mytable GROUP BY date

SET  @i=-1;
SELECT t.time, ifnull(num,0) AS count FROM 
	(SELECT DATE_SUB( NOW(),INTERVAL ( (@i:=@i+1) ) HOUR ) AS 'time' 
	FROM  mysql.help_category where @i<23) 
AS t 
LEFT JOIN 
	(SELECT DATE_FORMAT(DATE_SUB( create_time,INTERVAL MINUTE(NOW())-60 MINUTE ) ,'%Y-%m-%d %H') AS date, count(*) AS num 
	FROM mytable GROUP BY date ) 
AS sa 
ON sa.date = DATE_FORMAT( t.time,'%Y-%m-%d %H')  GROUP BY t.time

 SELECT
      hour(表_时间)  hour,
      count(表_id) count
    FROM 表_name
    //限制年月日（current_date  2022-03-05）
    WHERE  date_format(表_时间, '%Y-%m-%d') = current_date//格式化时间
    GROUP BY date_format(表_时间, '%Y%m%d-%H'), hour//按每小时分组