Difference between Primary Key and Foreign Key

Difference between Primary Key and Foreign Key
Difference-between-primary-key-and-foreign-key So the difference between Primary Key and Foreign Key is the most asked question of the interview. This is a very important concept. Before discussing the differences first we have to understand what is the primary key and foreign key. What is Primary Key: A primary key is a one-column or combination of the column with a unique value for each row or tuple. The value of the primary key must be unique within the table. The purpose is ...
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What is candidate key in DBMS?

candidate_key
What is Candidate Key in DBMS? A Candidate Key in DBMS is a minimal set of columns/attributes that can be used to uniquely identify a single/every tuple or row in a relation. Candidate Keys are determined during database design based on the underlying business rules of the database. After finding all possible candidate keys in a relation.DBA choose one key as a primary key. Consider the following relation in the context of a business firm: candidate key  E...
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