Is there any name for unique keys?

What is unique key in simple words?

A unique key is a set of one or more than one fields/columns of a table that uniquely identify a record in a database table. You can say that it is little like primary key but it can accept only one null value and it cannot have duplicate values.

Which key is a unique key?

Unique key is a constraint that is used to uniquely identify a tuple in a table. Multiple unique keys can present in a table. ... Difference between Primary Key and Unique Key.Primary KeyUnique KeyOnly one primary key can be present in a tableMultiple Unique Keys can be present in a table

How many unique keys are there?

Key differences between Primary and Unique Key A table cannot have more than one primary key in a relational database, while there can be multiple unique keys per table. A primary key column cannot contain NULL values, whereas a unique key can have NULL values, but only one NULL is allowed in a table.

What is unique key example?

A unique key is a group of one or more than one fields or columns of a table which uniquely identify database record. A unique key is the same as a primary key, but it can accept one null value for a table column. It also cannot contain identical values.