Thanks everyone for the replies..
I changed my script like this:
SELECT
ISNULL(C.containerCode, '') + ':' + ISNULL(C.containerName, '') as display,
C.containerCode AS code
FROM Containers C
INNER JOIN ContainersTypes CT ON
CT.containerTypeSqlId = C.containerTypeSqlId AND
CT.containerTypeIncId = C.containerTypeIncId
WHEREC.isDeleted = 0
ORDER BY display