what is primary key

The primary key of a relational table uniquely identifies each record in the table. It can either be a normal attribute that is guaranteed to be unique (such as Social Security Number in a table with no more than one record per person) or it can be generated by the DBMS (such as a globally unique identifier, or GUID, in Microsoft SQL Server). Primary keys may consist of a single attribute or multiple attributes in combination.

a primary key is used also as a constraint to provide an set of rules to the specific query and primary key is not having a null values

hmmm
*Name

*your opinion/answer:

Please enter atleast 250 characters.

Related Questions & Answers:

Difference between a primary key and a unique key in SQL?

how to lock the key pad of nokia n73 me?

What is best and latest PC Security?

What is Candidate Key in Database?

Difference between Primary Key and Alternate Key ?

wht is the difference between super key and candidate key