Question

What is the difference between a primary key and a foreign key as used in data base

Answer 1

Explanation:

Difference between Primary Key and Foreign Key. Primary key uniquely identify a record in the table. Foreign key is a field in the table that is primary key in another table. ... By default, Primary key is clustered index and data in the database table is physically organized in the sequence of clustered index.

Answer 2

Explanation:

Primary key is a unique value that identifies a row or data value of a field. As it is a unique value it is not used in other tables of same database.

Foreign key is the primary key in another table if same database. Foreign key is only applicable when a 2nd table is created in the database.