Foreign keys provide the building blocks for relating tables. For example, in a customer order table, the salesperson field might contain an employee number.

A primary key is a field used to uniquely identify every record in the database. Sometime primary keys are obvious, for example a car license plate could be used to uniquely identify cars. Often ...

For National 5 Computing Science, revise the use of primary and foreign keys and the difference between flat file and relational databases.