Functional Dependency in DBMS | Functional Dependency in DBMS with Example

What is Functional Dependency ?

A functional dependency defines the relationship between two attributes, typically between a prime attribute (primary key) and non-prime attributes. If for a table X containing attributes A and B, among which the attribute A is a primary key then the functional dependency is defined as:

A->B

Example for Functional Dependency:

Emp_ID->Emp_Name, Address, Contact_No

Emp_Name, Address, and Contact_No depends on Emp_ID, i.e. given an Emp_ID we can get the information on the employee details corresponding to the emp_id.