Need help with populating a column with a sequence number (I think) 2

[dinzana]

Hello there and thank you in advance. I am trying to populate a column (week_number) in my employee table. I need to insert a 1 at the first entry_date and then increment by 1 for every entry_date after, in sequence for EACH employee. The issue is, each employee can have a different entry_date from another employee. How do I accomplish this in SQL to include in a view? thanks for looking!

 

[bborissov]

SELECT Employee_Id,
       Entry_Date,
       ROW_NUMBER() OVER (PARTITION BY Employee_Id ORDER BY Employee_Id, Entry_Date) AS Week_Number
FROM...

NOT TESTED!

Borislav Borissov
VFP9 SP2, SQL Server

 

[TamarGranor]

You need to use OVER with ROW_NUMBER(). This is untested, but should give you the idea.

UPDATE YourTable
   SET Week_Number = RecNos.Week_Number
   FROM (SELECT Employee_ID, Entry_Date, 
                ROW_NUMBER() OVER (ORDER BY Entry_Date) AS Week_Number
           FROM YourTable) RecNos
   WHERE YourTable.Employee_ID = RecNos.Employee_ID 
     AND YourTable.Entry_Date = RecNos.Entry_Date

I've written about this use of OVER:

http://www.tomorrowssolutionsllc.com/Articles/Getting the Top N for each Group.pdf

Just skip over the VFP portion of the article.

Tamar

 

[dinzana]

Thanks to you both for great solutions and speedy fast, thanks again!!!

D

 

[Olaf Doschke]

Just a side note, this should be obvious from the code: ROW_NUMBER just numbers rows. That this row number corresponds to week numbers relies on the rows having entry_dates in week distances. If you ever have a gap of a missing entry date, the row numbers will not reflect that by also having that gap.

It's often sufficient to rely on requirements fulfilled from the outset, just watch out the data is not inseparably connected.

Bye, Olaf.