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MySQL按时间统计每个小时记录数

时间:2018-04-09 14:59:08      阅读:168      评论:0      收藏:0      [点我收藏+]

标签:syntax   order   cas   index   comm   font   help   row   less   

MySQL按时间统计每个小时记录数

方案1:

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SELECT  @rownum := @rownum + 1 AS ID,
        CONCAT((CASE WHEN t.hour = 24 THEN 0 ELSE t.hour END),‘:00:00‘) AS TIME, COUNT(*) AS COUNT
FROM (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) r
GROUP 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;

上面的修改

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SELECT  @rownum := @rownum + 1 AS ID,
        CONCAT((CASE WHEN t.hour = 24 THEN 0 ELSE t.hour END),‘‘) AS TIME, COUNT(*) AS COUNT
FROM (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) r
GROUP BY TIME ORDER BY ID

方案2

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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

MySQL按时间统计每个小时记录数

标签:syntax   order   cas   index   comm   font   help   row   less   

原文地址:https://www.cnblogs.com/jpfss/p/8759199.html

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