How to update primary key

Question

Here is my problem - I have 2 tables:

1. WORKER, with columns |ID|OTHER_STAF| , where ID is primary key
2. FIRM, with columns |FPK|ID|SOME

Answer 1

Don't update the primary key. It could cause a lot of problems for you keeping your data intact, if you have any other tables referencing it.

Ideally, if you want a unique field that is updateable, create a new field.