In our previous article we have see the difference between Asp.Net Web Form and Asp.Net MVC, today we will see the difference between PK and UK.
Difference between Primary Key and Unique Key in SQL Server
|Primary Key||Unique Key|
|Primary Key creates a Clustered index||Unique Key creates a Non Clustered Index|
|Primary Key does not allow null value||Unique Key allows only 1 null value.|
|A table can have only 1 Primary Key||A table can have more then 1 Primary Key|
|Primary Key is a unique key identifier of the record||Unique-key is to prevent duplicate values in a column|
|Primary Key has to be unique.||Unique Key does not have to be the primary key.|
|In Primary Key column you can’t delete or change the value||In Unique Key column you can delete or changes it’s value|
I love to here from you if I miss any other difference then listed above.