Need Pattern for dynamic search of multiple sql tables

Users
-----------
Name nvarchar(20)
Nickname nvarchar(10)

SELECT Name, Nickname
FROM Users
WHERE
    Name = COALESCE(@name, Name) AND
    Nickname =  COALESCE(@nick, Nickname)

SELECT Name, Nickname
FROM Users
WHERE
    Name = 'brian' AND
    Nickname =  Nickname