sql - 连续行之间的日期差异

Question

我有一个具有以下结构的表

ID     Account Number     Date
1      1001               10/9/2011 (dd/mm/yyyy)
2      2001               1/9/2011 (dd/mm/yyyy)
3      2001               3/9/2011 (dd/mm/yyyy)
4      1001               12/9/2011 (dd/mm/yyyy)
5      3001               18/9/2011 (dd/mm/yyyy)
6      1001               20/9/2011 (dd/mm/yyyy)

基本上我想做的是有一个 Access 查询来计算连续记录但相同帐号的日期差异
预期的结果是!!

1001      10/9/2011 - 12/9/2011     2 days
1001      12/9/2011 - 20/9/2011     8 days
1001      20/9/2011                 NA

基本上我想做的是有一个 Access 查询来计算连续记录的日期差异，但对于相同的帐号，在上面的例子中是 1001。(日期不必显示在结果中)

我使用 Access 2003。

Answer 1

SELECT  T1.ID, 
        T1.AccountNumber, 
        T1.Date, 
        MIN(T2.Date) AS Date2, 
        DATEDIFF("D", T1.Date, MIN(T2.Date)) AS DaysDiff
FROM    YourTable T1
        LEFT JOIN YourTable T2
            ON T1.AccountNumber = T2.Accountnumber
            AND T2.Date > T1.Date
GROUP BY T1.ID, T1.AccountNumber, T1.Date;

或者

SELECT  ID,
        AccountNumber,
        Date,
        NextDate,
        DATEDIFF("D", Date, NextDate)
FROM    (   SELECT  ID, 
                    AccountNumber,
                    Date,
                    (   SELECT  MIN(Date) 
                        FROM    YourTable T2
                        WHERE   T2.Accountnumber = T1.AccountNumber
                        AND     T2.Date > T1.Date
                    ) AS NextDate
            FROM    YourTable T1
        ) AS T