SQL to select rows with the 2 most recent dates

Question

I'm currently struggling with a dataset in which snapshots are saved for multiple companies. That snapshot is performed once a week but is divided over 2 days. I already got the dataset to work with just one recent day with:

Where [TRANSDATE] = (SELECT MAX(TRANSDATE) FROM QBE_INVENTDIMPHYSLOGGING)

But how do I include the 2 most recent dates (always a Saturday and Sunday). So in case of August, that would be 20th of August and the 21st, but I can't use those dates as hard values because it will change every week and I only want to import the most recent weekend. Could anyone assist how to tackle this? Many thanks in advance!

Gr. Diana

Answer 1

On SQL Server, you may use TOP :

SELECT TOP 2 *
FROM QBE_INVENTDIMPHYSLOGGING
ORDER BY TRANSDATE DESC;

If you had to stick with your current subquery approach (which, by the way, is completely fine for finding rank 1 records), you could extend using:

SELECT *
FROM QBE_INVENTDIMPHYSLOGGING
WHERE TRANSDATE = (SELECT MAX(TRANSDATE) FROM QBE_INVENTDIMPHYSLOGGING) OR
      TRANSDATE = (SELECT MAX(TRANSDATE)
                   FROM QBE_INVENTDIMPHYSLOGGING
                   WHERE TRANSDATE < (SELECT MAX(TRANSDATE)
                                      FROM QBE_INVENTDIMPHYSLOGGING));

If you want to capture all ties, then use TOP 2 WITH TIES instead of the first option. You may also use the RANK() analytic function.

Answer 2

You can use

Where [TRANSDATE] IN (SELECT top 2 TRANSDATE FROM QBE_INVENTDIMPHYSLOGGING order by TRANSDATE desc)