Question

a table named school( containing data of students of the whole school) is created, where each record consists of several fields including admission number, roll number, name. which field out of these three should be set as the primary key and why?

Answer 1

A field which uniquely identifies each record in a table is known as primary key. Here,admission number is the primary key.

Answer 2

The admission number is the most suitable field to allotted the primary key.

Explanation:

• The primary key ensures that all the values entered in the corresponding field are unique that is none of them are duplicate and it does not allow NULL values either.
• The field of admission number is unique for each and every student who went, goes, or will go to the school.
• Moreover, there does not exist any student who is allowed to go to the school without issuing their respective admission number.
• Hence, the admission number cannot take NULL value either.
• Therefore it is the most appropriate field to be assigned a primary key.