Question

Creation Date   Account Number         FREQUENCY - 7
2/3/15 3:47 PM     7522461                    0
2/4/15 9:25 AM     7522461                    1
2/4/15 4:34 PM     7522461                    2
2/23/15 3:08 PM    7522461                    0
3/4/15 9:58 AM     7522461                    0
3/4/15 4:55 PM     7522461                    1
3/5/15 2:27 PM     7522461                    2
3/6/15 7:28 AM     7522461                    3
3/6/15 1:33 PM     7522461                    4
3/9/15 8:51 AM     7522461                    5

我需要了解如何计算在7天时间戳内重复的帐号＃的频率。例如：2/3/15 3:47 PM到2/4/15 4:34 PM属于7天内，因此第一次出现0，同一7天内第二次出现1，第三次出现在同一7次内天将2等等。

Answer 1

使用用户定义的变量来跟踪1周间隔的开始和一周内的计数器。当创建日期超过1周后，重置变量。

SELECT CreationDate, AccountNumber,
       @frequency := IF(CreationDate > DATE_ADD(@startdate, INTERVAL 7 DAY), 0, @frequency + 1) AS Frequency,
       @startdate := IF(CreationDate > DATE_ADD(@startdate, INTERVAL 7 DAY), CreationDate, @startDate)
FROM (SELECT CreationDate, AccountNumber
      FROM YourTable
      ORDER BY CreationDate) AS x
CROSS JOIN (SELECT @startdate := DATE('1900-01-01'), @frequency := 0) AS vars

DEMO

Answer 2

如果是MSSQL，请试试这个

SELECT CreationDate, AccountNumber,  
      (SELECT COUNT(*) 
         FROM YourTable t2 
        WHERE (DATEDIFF(day, t2.CreationDate, t1.CreationDate ) < 7 AND 
                  (DATEDIFF(day, t2.CreationDate, t1.CreationDate) > 0 OR 
                       (DATEDIFF(day, t2.CreationDate, t1.CreationDate) = 0 
                         AND DATEDIFF(second, t2.CreationDate, t1.CreationDate) > 0 
                       )
                   )
               ) 
          AND t2.AccountNumber = t1.AccountNumber) 
         FROM YourTable t1 
        order by  AccountNumber, CreationDate

如何在SQL中计算频率

2 个答案: