How to return default value from SQL query

Question

Is there any easy way to return single scalar or default value if query doesn\'t return any row?

At this moment I have something like this code example:

Answer 1

Assuming the name is not nullable and that Id is unique so can match at most one row.

 SELECT 
    ISNULL(MAX(Name),'John Doe')
 FROM 
    Users 
 WHERE 
    Id = @UserId