Basic Principles


Notes from my Exercise Book

Several of the more common models of databases include:

  1. Hierarchical
  2. Network
  3. Relational

It is relational databases that are used more commonly than their alternative, flat-file databases. They depend on a sound theoretical basis in relational algebra.

Definitions for relational databases:

Relational Databases

"The relational model, which is rooted primarily in the mathematical principles of set theory and predicate logic, supports easy data retrieval, enforces data integrity (data accuracy and consistency), and provides a database structure independent of the applications accessing the stored data." (Oppel and Sheldon, 2009)

Here are some further definitions that would seem to overlap with the ones provided in my notes above, but those I have already listed are utilised more in the context of SQL whereas the following are used more in actual relational theory. Definitions from Oppel and Sheldon (2009). SQL: A Beginner's Guide, Third Edition. New York et al: McGraw Hill:

You may find these links useful for pursuing a personal interest in databases and SQL:


© 2016-2020 Leo Coroneos
Certificate IV in Information Technology
South Regional TAFE, Albany WA Australia