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.
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