Question

Differentiate between
primary key and index

Answer 1

Difference between an Index and aPrimary Key. ... Because they are unique and not null, these values (or value if your primary key is a single column) can then be used to identify a single row in the table every time. In most if not all database platforms thePrimary Key will have an index created 

Answer 2

Difference between an Index and a Primary Key. ... Because they are unique and not null, these values (or value if your primary key is a single column) can then be used to identify a single row in the table every time. In most if not all database platforms the Primary Key will have an index created on it.