Query to show all but not set ones

can any one help i need to do a query for our user database

I have two colums.

One is Department
One is Realname

What i would like to do is to list all users apart from those who’s department = no longer employed

So, select all rows from the table where the department is not ‘no longer employed’
I’m sure it won’t be too hard to translate that in SQL. Give it a try, and if you can’t get it to work, post your query here.