Learn Access Now! Chapter 12 Previous Section in Chapter 13 Chapter 14

Chapter 13: Understanding Data Relationships

(This is section 3 of 3 in this chapter)

Summary

Access lets you set up very complex and very powerful data relationships. The ability to implement relationships between tables lets you reap many benefits which can make you more productive and your database more efficient. This chapter has introduced you to both the concepts of relational databases and the steps necessary to put them into action.

Before you move on to Chapter 14, make sure you understand the following key concepts:

A relational database is a database in which you establish links between data in one table and data in another.
You establish a one-to-one relationship when a record in one table can have only one corresponding record in another table.
You establish a one-to-many relationship when a record in one table can have more than one corresponding record in another table.
You establish a many-to-many relationship when any record in one table can have more than one corresponding record in another table, and vice versa.
Within index tables, keys establish links with information in other tables.
Keys need to be unique and cannot be undefined (null). In the table that owns the key, the key field is called a primary key. If a key field is used to establish a link with another table, then in the other table it is a foreign key.
In Access, you use the Relationships option from the Tools menu to create links between tables.
Referential integrity means that the use of keys across a link is both consistent and correct. You can instruct Access to enforce referential integrity.

In Chapter 14, you will revisit creating Access reports. There you will learn how to use the report Design window, in detail.

Learn Access Now! Chapter 12 Previous Section in Chapter 13 Chapter 14