7.1.1+Key+Field

=__Definition of the term "Key field"__=

A "Key Field" is the ID used to identify a record.

There are two types of Keys:
 * A Primary Key that is used to uniquely identify a record, eg. a teacher record
 * A Unique Key is a key that is composed of two or more field entries used to uniquely identify the record. Eg. birthday, gender, phone number etc.

__**Example**__
The Unique Key is composed of the Primary Key (the ID number), The Initials if the Students and their birth years.
 * ID || # || First || Last || Year ||
 * 0001DG1993 || 0001 || Daniel || G || 1993 ||
 * 0002JB1992 || 0002 || Johann || B || 1992 ||

Created by: Daniel Gillo Last modification: 2nd September 2011

Sources:
 * Jones, Richard. __Computer Science Java Enabled__. Victoria: IBID Press, 2004