Question

我有一张这样的表

CREATE TABLE news
(
Id         INT NOT NULL auto_increment,
Headline   VARCHAR (255) NULL,
InDateTime   DATETIME NULL
)

如何获取每秒记录数（InDateTime）？

我正在使用Mysql

样本记录：

578921,   'headline1', '8/20/2012 12:01:53 PM' 
578922,   'headline2', '8/20/2012 12:01:53 PM' 
578923,   'headline3', '8/20/2012 12:01:53 PM' 
578924,   'headline4', '8/20/2012 12:01:59 PM' 
578925,   'headline5', '8/20/2012 12:01:59 PM' 
578926,   'headline6', '8/20/2012 12:01:59 PM' 
578927,   'headline7', '8/20/2012 12:01:59 PM' 
578928,   'headline8', '8/20/2012 12:02:03 PM'

预期产出：

time,                    count
'8/20/2012 12:01:53 PM', 3
'8/20/2012 12:01:59 PM', 4
'8/20/2012 12:02:03 PM', 1

Answer 1

让你厌倦了：

SELECT COUNT(id), InDateTime
FROM news
GROUP BY InDateTime

Answer 2

您希望根据time对结果进行分组。对于每个time，您需要行数。所以你可以使用这个查询。

select time, count(*)
from news
group by time

此处group by time将创建单独的不同time值组。 select time将在第一列中选择时间。 count(*)将给出包含该值的行数。

你读得更好this

Answer 3

任何转化的最简单方法

SELECT `time`, COUNT(*) totalCount
FROM tableName
GROUP by `time

Answer 4

SELECT InDateTime AS Time, COUNT(InDateTime) AS Count
FROM NEWS
GROUP BY InDateTime

<强>结果

Time                     Count
2012-08-20 12:01:53.000   3
2012-08-20 12:01:59.000   4
2012-08-20 12:02:03.000   1

选择每秒最大计数

4 个答案: