How to return default value from SQL query

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

Try this

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

Try ISNULL or COALESCE:

SELECT ISNULL((SELECT TOP 1 Name FROM Users WHERE Id = @UserId), 'John Doe')

The inner select will return nothing if no user exist with this id, the isnull will solve this case.

Related