How to return default value from SQL query
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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:

    IF (EXISTS (SELECT * FROM Users WHERE Id = @UserId))  
    	SELECT Name FROM Users WHERE Id = @UserId  
    ELSE
        --default value
    	SELECT 'John Doe'

How to do that in better way without using IF-ELSE?