Question

How many Primary keys can have in a table?

a) Only 1

b) Only 2

c) Depends on no of Columns

d) Depends on DBA

Answer 1

Answer is Only 1

The primary key can consist of a single or combination of the field that uniquely identifies each record in a table. It cannot be null or empty. A table may have duplicate columns, but it can contain only one primary key.