Please explain, what is functional dependency in databases? Solution Definition:

Question

Explanation / Answer

Definition: A functional dependency occurs when one attribute in a relation uniquely determines another attribute. This can be written A -> B which would be the same as stating "B is functionally dependent upon A." Also Known As: Database Dependency Examples: In a table listing employee characteristics including Social Security Number (SSN) and name, it can be said that name is functionally dependent upon SSN (or SSN -> name) because an employee's name can be uniquely determined from their SSN. However, the reverse statement (name -> SSN) is not true because more than one employee can have the same name but different SSNs.

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects