1 2 3 4 5 6 7 | SELECT @rownum := @rownum + 1 AS ID, CONCAT((CASE WHEN t.hour = 24 THEN 0 ELSE t.hour END),‘:00:00‘) AS TIME, COUNT(*) AS COUNTFROM (SELECT id, HOUR(DATE_FORMAT(createtime,‘%H:%i:%s‘))+1 AS HOUR FROM baby WHERE DATE_FORMAT(createtime,‘%Y-%m-%d‘)=‘2016-10-16‘) t, (SELECT @rownum := 0) rGROUP BY TIME ORDER BY ID//这个计数, 是LESS THAN TIME的计数方法, 即11:xx:xx的记录是记到12:00:00下面的, 而不是11:00:00; |
1 2 3 4 5 | SELECT @rownum := @rownum + 1 AS ID, CONCAT((CASE WHEN t.hour = 24 THEN 0 ELSE t.hour END),‘‘) AS TIME, COUNT(*) AS COUNTFROM (SELECT id, HOUR(DATE_FORMAT(createtime,‘%H:%i:%s‘)) AS HOUR FROM baby WHERE DATE_FORMAT(createtime,‘%Y-%m-%d‘)=‘2016-10-16‘) t, (SELECT @rownum := 0) rGROUP BY TIME ORDER BY ID |
1 | SELECT LEFT( createtime, 13 ) , COUNT( * ) FROM baby WHERE DATE_FORMAT(createtime,‘%Y-%m-%d‘)=‘2016-10-16‘ GROUP BY LEFT( createtime, 13 ) |
如果当前小时无数据目前无法返回0 ！ 不知道怎么处理了
原文：https://www.cnblogs.com/jpfss/p/8759199.html