Professor Adams' Lecture Materials

Learning Objective M05-06: Use multiplicities to implement foreign keys in relational tables.

UML Class Models Support DB Planning

The database will contain.

One table for each class, plus.
One table to support each many-to-many relationship.

Multiplicities indicate location of foreign keys for one-to-many associations.

Multiplicities indicate linking tables for many-to-many associations.

One-to-Many Associations

The primary key of Customer becomes the foreign key in Order. General rule: look at the maximum multiplicities on each side of the association. The primary key of the class on the 1 side becomes the foreign key of the class on the * side.

Many-to-Many Associations

When the maximum multiplicity on both sides is *, implement with a new linking table in Access. The primary key of the new table is the combination of the primary keys of the linked tables.

Resulting DB Tables and Relationships

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