A database (🗺) is a collection of data that is organised structurally according to a specific well-defined set of rules.
Database normalisation is organising data in a database such that errors and anomalies are avoided. To normalise a database, we use the so-called normal forms:
- The first normal form requires all the attribute values to be atomic.
- The second normal form requires to have no partial dependencies.
- The third normal form requires to have no transitive dependencies.
A foreign key is a primary key included within another table. We use foreign keys to relate tables between each other.