I'm fairly new to C# and RavenDB, so please excuse my lack of understanding.

I currently have a Windows Form Application. In one of the forms, I have two text boxes and one button. These two text boxes serve as the username and password inputs and the button is obviously there so that the user can login. When the user clicks on the button, a method is called and saves the content of the two inputs in two string variables.

At the moment, in my RavenDB Database, I have created two samples of username and password.

How do I appropriately check whether the username and password given from the user exists in the database. 

Any help is really appreciated.