Primary key data

Hi Gerardo

The primary key of a relational table uniquely identifies each record in the table. It has to be unique such as employee number or Product code.

A good example would be a table containing all the names of students in a school.

You cannot use the students names as an identifyer because there will certainly be students with the same names but by making the Student ID as the primary key the system will warn you if you try and create a new student with an existing ID number.

The ID number can then be used in other tables to refer to the students

Hope this helps

Carlos