Primary Key | MCQs

Explanation

An Alternate key is any candidate key not chosen as the primary key.

It can still uniquely identify records, but isn't used as the main identifier.

Explanation

A primary key is a field or set of fields with values that are unique throughout a table.

Values of the key can be used to refer to entire records, because each record has a different value for the key.

Each table can only have one primary key.

Explanation

A primary key must be unique for each record and never change.

Zip code is not unique (many people can share the same zip code), so it's not suitable as a primary key.

Explanation

The Primary Key consisting of two or more attributes is called Composite Key.