Question

我有一个名为messages的表，其中包含发件人和收件人之间的IM记录。

这4个字段是：Date，Timestamp Senderid，Recipientid。

如何在一分钟内找到收到回复的邮件百分比？

Answer 1

Declare @RespondedMessagesCount INT = 
(Select Count(*) from messages m1

INNER JOIN messages m2
on m1.sender = m2.recipient
and m1.recipient = m1.sender

WHERE ABS(DateDiff(minute, m1.Date, m2.Date)) < 1),
@AllMessagesCount INT = (Select count(*) from messages)

Select Cast(@RespondedMessagesCount as float)/@AllMessagesCount * 100

Answer 2

我不是专家，但这是我对MySQL的回答

架构：

CREATE TABLE messages
    (`Date` varchar(25), `Timestamp` varchar(25), `Senderid` Int, `Recipientid` Int )
;

INSERT INTO messages
    (`Date`, `Timestamp`,  `Senderid`, `Recipientid`  )
VALUES
    ('2017-02-27', '21:28:23', 1, 2),
    ('2017-02-27', '21:28:26', 2, 1),
    ('2017-02-27', '21:28:27', 1, 4),
    ('2017-02-27', '21:29:28', 4, 1),
    ('2017-02-27', '21:28:28', 3, 1)
;

查询：

select 
100*(
  SELECT count(*) FROM
  (
    SELECT 
      msg.Recipientid as Senderid,
      msg.Senderid as Recipientid,  
      TIMESTAMPDIFF(SECOND, CONCAT(messages.Date,' ',messages.Timestamp), CONCAT(msg.Date,' ',msg.Timestamp)) as seconds
    FROM messages 
      INNER JOIN messages msg ON messages.Recipientid=msg.Senderid
    WHERE
      msg.Recipientid=messages.Senderid
    ) as results
  WHERE seconds<=60 AND seconds>0
)/ (SELECT count(*) FROM messages)

以下是工作示例fiddle

如何在一分钟内找到收到回复的邮件百分比？

2 个答案: