Question

I have the following table with 10 unique rows, BookingID is a FK containing a random number. The number doesn’t need to be in sequence.

BookingID, Description
1000       Foo
3000       Bar
1500       Zoo

I need to insert an sequential index called ID which goes from 1..x

how do I do that in SQL Server 2005? I was thinking to write a cursor and x=x+1 but maybe there is a better way?

This is the result I want

Id, BookingID, Description
1   1000       Foo
2   3000       Bar
3   1500       Zoo

Answer 1

This:

SELECT ROW_NUMBER() OVER(ORDER BY t.bookingid) AS id,
       t.bookingid,
       t.description
  FROM YOUR_TABLE t

…will produce:

id  bookingid   description
----------------------------
1   1000        Foo
2   3000        Bar
3   1500        Zoo

To update the existing id column, use:

WITH cte AS (
   SELECT t.id,
          ROW_NUMBER() OVER(ORDER BY t.bookingid) AS rank,
          t.bookingid,
          t.description
     FROM YOUR_TABLE t)
UPDATE cte
   SET id = rank