Relationships and entity relationship diagrams A table in a database holds the attributes for one entity only. Data can then be added in the form of records.

It is necessary to include relationship descriptions like this when creating an entity relationship diagram. If we added a third entity (Sport), we would have another relationship to add.

The grammars used to generate entity-relationship diagrams and object-oriented conceptual models, for example, provide separate constructs for representing entities and attributes. The grammars used ...