is there anyway to add a primary autonumber key to an already existing database table

Question

i have inherited a database application from someone else and there are a few tables that dont have any primary keys. I want to add a new column into an already existing table and have it autonumber (starting from 1). how would i go about doing this?

Answer 1

The SQL Server syntax is:

ALTER TABLE SomeTable ADD
    ID int NOT NULL IDENTITY(1, 1),
    CONSTRAINT PK_SomeTable PRIMARY KEY [NON]CLUSTERED (ID)

Answer 2

"i need to delete a number of rows and the only way i can do it now is by using the timestamp field. It would be much easier if i could say "delete from tableA where id = 100""

And how would you decide which id's to delete ?