SQL: Select rows with a column value that occurs at least N times?

Question

Suppose I have a SQL table \"Celebrities\" with two columns: \"fname\" and \"lname\":

fname    | lname    
---------+-------  
Bill     | Clinton
Bill     |          


        

Answer 1

select fname, lname
from 
  (
    select fname, lname, count(*) over(partition by lname) as lcount
    from Celebrities
  ) as S
where lcount > 1

Tested in SQL Server 2008. Might work in other DBMS that support count(*) over(...)