Foreign Key

A Foreign Key accesses data in some other related table via its Primary Key.




See also

The nature of Foreign Keys

A Foreign Key consists of a collection of columns (UML Attributes) that together have some operational meaning (they enforce a relationship to the Primary Key in the other table)



Foreign keys are modeled in Enterprise Architect as operations with the stereotype FK

The operation's parameters become the columns involved in the key


Necessity of Use

It is not necessary to define a Foreign Key just to access another table through its Primary Key

Foreign Keys are a feature of some database management systems, providing 'extras' such as referential integrity checking that prevents the deletion of a record if its Primary Key value exists in some other table's Foreign Key

The same thing can be achieved programmatically


Learn more