SQL duplicates with different primary keys

Question

I have a table in this form:

id | firstname | lastname
---+-----------+----------
1  | alex      | marti
2  | mark      | finger
3  | alex      | marti
4  | ted          


        

Answer 1

Select Id, First_Name, Last_Name
FROM
(
Select Id, First_Name, Last_Name,
Count() Over (Partition By First_Name,Last_Name) Count
From Emp
) AS T
Where T.Count > 1