how to catch NULL values using case statement

Question

Hi, here in this query I want to replace the values in Person.Contact of Adventureworks database with some new values. The below query case statement is working fine for other values but I am not able to change the values those are in NULL. I am using SQL Server. Any help is appreciated.

select contactid,Title,FirstName,MiddleName,
case MiddleName
when 'R.' then 'Robert'
when 'B.' then 'Bids'
when 'J.' then 'John'
when is null then 'New Name'
else 'No Name'
end, LastName from Person.Contact

Answer 1

case 
when MiddleName is null then ...
when MiddleName = 'R' then ...
end

Answer 2

I'd use the ISNULL function - it will return the value given if the field is NULL:

select contactid,Title,FirstName,MiddleName,
case ISNULL(MiddleName, 'NULLVALUE')
when 'R.' then 'Robert'
when 'B.' then 'Bids'
when 'J.' then 'John'
when 'NULLVALUE' then 'New Name'
else 'No Name'
end, LastName from Person.Contact