Custom PrimaryKey Generation with autoincrement

Question

I need to define and generate primary key for 2 or more tables.

Tables hold same type of data but FOR Some BUSINESS RULES we have to make them separate say like

Answer 1

If your proposed 2 tables have the same columns, then I see no reason why you should make them separate tables at all. Create a column for storing the type of customer (international or domestic) and keep track that way. Why use 2 tables when 1 will suffice?