How to update Identity Column in SQL Server?

If got your question right you want to do something like

update table
set identity_column_name = some value

Let me tell you, it is not an easy process and it is not advisable to use it, as there may be some foreign key associated on it.

But here are steps to do it, Please take a back-up of table

Step 1- Select design view of the table

Step 2- Turn off the identity column

Now you can use the update query.

Now redo the step 1 and step 2 and Turn on the identity column

Reference

You need to

set identity_insert YourTable ON

Then delete your row and reinsert it with different identity.

Once you have done the insert don't forget to turn identity_insert off

set identity_insert YourTable OFF

You can not update identity column.

SQL Server does not allow to update the identity column unlike what you can do with other columns with an update statement.

Although there are some alternatives to achieve a similar kind of requirement.

• When Identity column value needs to be updated for new records

Use DBCC CHECKIDENT which checks the current identity value for the table and if it's needed, changes the identity value.

DBCC CHECKIDENT('tableName', RESEED, NEW_RESEED_VALUE)

• When Identity column value needs to be updated for existing records

Use IDENTITY_INSERT which allows explicit values to be inserted into the identity column of a table.

SET IDENTITY_INSERT YourTable {ON|OFF}

Example:

-- Set Identity insert on so that value can be inserted into this column
SET IDENTITY_INSERT YourTable ON
GO
-- Insert the record which you want to update with new value in the identity column
INSERT INTO YourTable(IdentityCol, otherCol) VALUES(13,'myValue')
GO
-- Delete the old row of which you have inserted a copy (above) (make sure about FK's)
DELETE FROM YourTable WHERE ID=3
GO
--Now set the idenetity_insert OFF to back to the previous track
SET IDENTITY_INSERT YourTable OFF