Violation of PRIMARY KEY constraint ''. Cannot insert duplicate key in object ''. The duplicate key value is ()

You might see the application guys coming out to you with the following error or you might encounter this error sometime when you are doing some insert or may be running a sp which is doing some insert.

"Violation of PRIMARY KEY constraint 'Constraintname'. Cannot insert duplicate key in object 'tablename'. The duplicate key value is (duplicatevalue)

As the name itself says, its pretty simple, the application or insert statement is trying to insert something into a column which is primary key and the value which is trying to insert is already existing in column

You need to either delete the duplicate key or have to modify you insert to resolve this.