What is surrogate key?
Surrogated keys are always integer or numeric. It is useful because the natural primary key can change and this makes updates more difficult .Surrogate key is the bassically a type of sunsitution key for the primary key . It is just a unique identifier or number for each row that can be used for the primary key to the table. The only requirement for a surrogate primary key is that it is unique for each row in the table..