Primary Keys in Oracle and SQL Server

Question

What\'s the best practice for handling primary keys using an ORM over Oracle or SQL Server?

Oracle - Should I use a sequence and a trigger or let the OR

Answer 1

Sometimes, there is a natural, unique identifier for a table. For instance, each row in a User table can be uniquely identified by the UserName column. In that case, it may be best to use UserName as the primary key.

Also, consider tables used to form a many to many relationship. A UserGroupMembership table will contain UserId and GroupId columns, which should be the primary key, as the combination uniquely identifies the fact that a particular user is a member of a particular group.