Question

What is primary key and foreign key? give example for each?

Answer 1

The primary key: 1-It is used to remove a field
The foreign key:1-It is used to perform as primary key.

Answer 2

primary key:-

it is a uniquely identify a record in the table. ex:rollnumbers

foreign key:-

a foreign key is a field in one table that uniquely identifies a row of another table or the same table