5.5. Key Field

Fields in red color are primary key fields.

Every table has at least one primary key field.

Primary key fields have the following meanings, to list a few:

Social security number is another example. The computer system responds most quickly by looking for a specific social security number in its database than looking other fields like name. Besides, there are chances that multiple records associated with the provided name are returned by the search.

Refer to screen shot Figure 5-1.