Thank you, let me check it

Thank you, good to know. This seems a new feature, we don not need to do so in previous versions.

I cannot try this now, for I installed Ssdt tool,...

I installed the data tool, then I am able to edit the maintainance plan.

It is surprised to me that maintenance plan can be no longer edited and created if SSDT...

Thank you, will give a try.

Also my other part of the questions, if SQL data tool not installed, but just installed SSMS, can I edit or create maintenance plan?

It seems...

Thanks, I will give it a try

Ok thanks , will read.

This time I use school calendar table that has a flag that marks which are school days . It looks to me to count absense for the last 30...

Thanks. This time I mean how to query the last 30 days not any rolling days using school calendar table?

thank you. So far the last 30 days we consider it as calendar days similar like last month.

But suppose I have a school calendar table, it looks like for calculation...

But each schoolyear we will have to make a new calendar table.

I am wondering since I know for each student their first and last absent school day, there should...

If I don't have a schoolCalendar table, but Truantday table has all absent days of current school year for students, and I also know a start date and end date...

I do attach a data file for truantday in the attachment of the post counting back the eighth one.

Yes, include the last date of truant is helpful too.

It looks the code: PARTITION BY s.StudentID ORDER BY sc.SchoolDay ROWS BETWEEN 30 PRECEDING AND CURRENT ROW

and a cross join with school calendar table really does the work for...

Thank you Drew.

Let me check into it.

I would like to find out in every past 30 days(a month) the students has 2 days absent, or 3 days absent.

These are any sliding 30 days not only...