The Primary Key
Some
organizations use a special numbering system. For example, many
medical databases use the Social Security number to identify their
patients. Each of us has our own unique, social security number.
However, there are identity and security concerns about using SS
numbers.
In Microsoft Access the Primary Key should be an AutoNumber. As
you add new records, Access will use the next number
automatically.
Databases crunch numbers quickly. If the Primary Key is text, such
as a social security number, then each character must be evaluated
by the database one at a time. This process is slow.
3.
Try it: Review the Field Properties
tblCustomers is still open in Design View.
The Table
Tools are available.
Select the
first Field: ID
What Do
You See? The ID Field is indentified with a Key. It is Indexed
(No duplicates.)
It is also an AutoNumber. Keep
going, please.