Properly expressing foreign keys (which means understanding the possible semantic subtleties involved in various alternatives), singles out mastery of the data modeling process. And truly ...

In relational databases, it is a field in one table that is indexed in another. Foreign keys provide the building blocks for relating tables. For example, in a customer order table, the ...

Retaining an infinitude of Foreign Keys may cause future performance bottlenecks as transactional volume will get a performance hit by maintaining all those foreign keys and the indexes behind them.

I'm adding a table and subclass table to my DB. (Subclass table = table where the primary key joins to the primary key of another table, to give extra row information to some subset of the rows ...