Defining Relationships Between Tables
A well-designed Access database typically contains many interrelated tables, with each table containing a specific, narrowly defined set of data, without any duplicate information. This type of design is crucial to maintaining referential integrity—when you change a name, address, or other piece of data in one record, your change automatically appears in all related tables.
Imagine a database application that tracks customer purchases based on invoices. A proper design stores this information in four separate tables, as shown in Figure 34.2:
Figure 34.2. Note that each of the relationships between these four tables is tied to the primary key in one of the tables, shown in bold in the field list.
The Customers ...
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