Question

I have a table with 100 records with no PK.

I need to add random GUID to it. Before:

    First Name   Last Name   GUID
      John         Smith
      Alex         Smith
etc

After:

    First Name   Last Name   GUID
      John         Smith    34234234gyerfw
      Alex         Smith    werwer32r23r
etc

Currently I can do it by:

Creating an identity column with values, then make a while loop and generate newid().
Any option on how to do this without a loop?

Answer 1

Add the GUID column as NOT NULL with a default of NEWID()

ALTER TABLE
    [dbo].[Text]

ADD [GUID] uniqueidentifier NOT NULL DEFAULT NEWID()

This will automatically populate the existing rows, an you will not need to specify a guid when inserting records.