Question

我有一个表，其中有一列称为时间戳记（YYYY-MM-DD HH:MM:SS）和消息。我将如何显示每分钟发送的邮件数量（不只是在给定的时间内）。

我已经做到了，但是每次都可以。我将如何进行更改计算从HH-00：00发送到HH：01：00的数量，以此类推。

SELECT timestamp, COUNT(*)
FROM Messages
GROUP BY timestamp
ORDER BY timestamp DESC

Answer 1

尝试：

SELECT HOUR(timestamp) AS Hour, 
       MINUTE(timestamp) AS minute, 
       COUNT(*) 
FROM Messages 
GROUP BY HOUR(timestamp), MINUTE(timestamp)
ORDER BY HOUR(timestamp) DESC, MINUTE(timestamp) DESC

Answer 2

SELECT TIMESTAMP(DATE(timestamp),MAKETIME(HOUR(timestamp),MINUTE(timestamp),0))
,COUNT(1) 
FROM 
Messages 
GROUP BY TIMESTAMP(DATE(timestamp),MAKETIME(HOUR(timestamp),MINUTE(timestamp),0))
ORDER BY TIMESTAMP(DATE(timestamp),MAKETIME(HOUR(timestamp),MINUTE(timestamp),0))

每分钟SQL的插入量

2 个答案: