SQL Server: how to add new identity column and populate column with ids?

Question

I have a table with huge amount of data. I\'d like to add extra column id and use it as a primary key. What is the better way to fill this column with values fr

Answer 1

If you want to add row numbers in a specific order you can do ROW_NUMBER() into a new table then drop the original one. However, depending on table size and other business constraints, you might not want to do that. This also implies that there is a logic according to which you will want the table sorted.

SELECT ROW_NUMBER() OVER (ORDER BY COL1, COL2, COL3, ETC.) AS ID, *
INTO NEW_TABLE
FROM ORIGINAL_TABLE