renumber primary key

Question

How would I reset the primary key counter on a sql table and update each row with a new primary key?

Answer 1

This may or not be MS SQL specific, but: TRUNCATE TABLE resets the identity counter, so one way to do this quick and dirty would be to 1) Do a Backup 2) Copy table contents to temp table: 3) Copy temp table contents back to table (which has the identity column):

SELECT Field1, Field2 INTO #MyTable FROM MyTable

TRUNCATE TABLE MyTable

INSERT INTO MyTable
(Field1, Field2)
SELECT Field1, Field2 FROM #MyTable

SELECT * FROM MyTable
-----------------------------------
ID    Field1    Field2
1     Value1    Value2