In a relational database, such as Access, you break various subjects, such as clients and projects, into separate tables.
Relationships specify how you want those tables to relate to each other, i.e. each project belongs to a client, and each client can have many projects. Relationships in Access, like relationships in real life, can be somewhat complicated. In Access, as in life, you can have a
- one-to-many, or
- many-to-many relationship.
Thatthe Access versionis what this module is all about.
Up until now, you may have used relationships to enhance query performance or perhaps worked only with the Access default relationships.
Relationships are maintained using the Relationships option from the Tools menu.
You can see the base set of relationships for our course database here in this figure:
By the end of this module, you will know how to:
- Identify different types of relationships used in Access
- Create one-to-one and one-to-many relationships
- Create a many-to-many relationship
- Use relationships to manage referential integrity
- Set the Cascade Update and Cascade Delete options for relationships
Relationships can greatly affect the integrity of the information going into your database. Let us get started.
In the next lesson, you will learn how to identify different types of relationships used in Access.