Database Reference
In-Depth Information
17
Click the
Title
field name. Then on the
Fields
tool tab, in the
Properties
group, click
255
in the
Field Size
box to select it, enter
50
, and press the
Enter
key.
18
Enter the following information in the first record, pressing the
Tab
key after each
entry:
FirstName
Karen
LastName
Berg
2
Title
Owner
The Employees table is now ready for you to enter more employee records.
19
Close the
Employees
table, clicking
Yes
to save changes to the layout when
prompted.
CLEAN UP
Keep the MyTables database open for use in the last exercise.
Defining relationships between tables
In Access, a relationship is an association that links the primary key field in one table to
a field that contains the same information in another table. The field in the other table
is called the
foreign key
. For example, if customer accounts are assigned to specific sales
employees, you can establish a relationship by linking the primary key EmployeeID field
in the Employees table with the foreign key EmployeeID field in the Customers table. Each
customer account is assigned to only one employee, but each employee can manage many
customer accounts, so this type of relationship—the most common—is known as a
one-to-
many relationship
.
Similarly, if every order is associated with a customer, you can establish a relationship
by linking the primary key CustomerID field in the Customers table and foreign key
CustomerID field in the Orders table. Each order is placed by only one customer, but
each customer can place many orders. So again, this is a one-to-many relationship.
