Date Difference between consecutive rows

I have a table with following structure

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)

Basically what i would like to do is have an access query that calculates the date difference for consecutive records but for the same account number The expected result would be !!

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

Basically what i would like to do is have an access query that calculates the date difference for consecutive records but for the same account number , in the above example would be 1001. (the dates don't have to be shown in the result)

I use access 2003.

Solution 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;

or

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

Solution 2:

you ca also use LAG analytical function to get the desired results as :

Suppose below is your input table:

id  account_number  account_date
1     1001          9/10/2011
2     2001          9/1/2011
3     2001          9/3/2011
4     1001          9/12/2011
5     3001          9/18/2011
6     1001          9/20/2011


select id,account_number,account_date,
datediff(day,lag(account_date,1) over (partition by account_number order by account_date asc),account_date)
as day_diffrence
from yourtable;

Here is your output:

id  account_number  account_date    day_diffrence
1     1001           9/10/2011    NULL
4     1001           9/12/2011    2
6     1001           9/20/2011    8
2     2001           9/1/2011     NULL
3     2001           9/3/2011     2
5     3001           9/18/2011    NULL

Solution 3:

You can add a WHERE statement for the account number, if required. Your table is called t4

SELECT 
   t4.ID, 
   t4.AccountNumber, 
   t4.AcDate, 
   (SELECT TOP 1 AcDate 
    FROM t4 b 
    WHERE b.AccountNumber=t4.AccountNumber And b.AcDate>t4.AcDate 
    ORDER BY AcDate DESC, ID) AS NextDate, 
   [NextDate]-[AcDate] AS Diff
FROM t4
ORDER BY t4.AcDate;