How to store table rows in a temp table

Question

I have a table with around 600000 records. I want to reseed the identity column of this table. Here's my plan:

1. Store contents of this table in temp table
2. Delete all records from this table
3. Reseed identity
4. Insert records from that temp table into this one

So how do I store this table into a temp one?

Answer 1

If there is nothing else behind the scene then try this:

SET IDENTITY_INSERT TABLE_NAME ON
GO

UPDATE  CTE
SET     ID = RN
FROM
(
    SELECT  ID, ROW_NUMBER() OVER(ORDER BY ID) AS RN
    FROM    TABLE_NAME
) AS CTE

SET IDENTITY_INSERT TABLE_NAME OFF
GO

DBCC CHECKIDENT('TABLE_NAME', RESEED, 600001)
GO