Database Management Systems · Foundations

Functional dependencies

One column's value fully determines another's, e.g. knowing the ID tells you the name.

Also known as: FDs, attribute dependency, closure of attributes.

Start a lesson on Functional dependencies

Learn first

• Relational model: Data as tables of rows and columns, with no other structure implied.

Leads to

• Normalization: Splitting tables so each fact lives in exactly one place, to avoid update anomalies.

Related topics

• Normalization: Splitting tables so each fact lives in exactly one place, to avoid update anomalies.
• Entity-relationship modeling: Sketching entities and their relationships as a diagram before turning them into tables.