How do I update a Table from another Table with exactly the same Format on SQL Server 2008

Question

I have a backup like this:

Select * Into BACKUP From ORIGINAL

Then I need to restore some data from that backup, how do I update from that table, I can't Insert Into nor Drop Table because of the Foreign Keys

Answer 1

This is the basic structure for SQL that will update the ORIGINAL table with the values from the BACKUP table, joining on a presumed common field which would be the primary key. Add a WHERE clause if you don't want every field 'restored'

UPDATE ORIGINAL
SET 
Field1 = [BACKUP].Field1,
Field2 = [BACKUP].Field2,
Field3 = .....
FROM ORIGINAL
INNER JOIN [BACKUP] ON ORIGINAL.PKField = [BACKUP].PKField