I have a table with three fields, FirstName, LastName and Email.
Here's some dummy data:
FirstName | LastName | Email
Adam West firstname.lastname@example.org
Joe Schmoe NULL
SELECT CONCAT(FirstName, LastName, Email) as Vitals FROM MEMBERS
ISNULL(FirstName, '<BlankValue>') -- In SQL Server IFNULL(Firstname, '<BlankValue>') -- In MySQL
CONCAT(ISNULL(FirstName,''),ISNULL(LastName,''),ISNULL(Email,'')) -- In SQL Server CONCAT(IFNULL(FirstName,''),IFNULL(LastName,''),IFNULL(Email,'')) -- In MySQL
would return the same thing without the null issue (and a blank string where nulls should be).