I have a trench containing five types of ducts. I have created fields the trenches: Type1, Type2, Type3, ...
The values in each field are the numbers of each type of duct that the trench contains.
eg. lets say that one trench contains 2 ducts of type one and one duct of type 2, then I would like to label it something like this:
The other types are NULL. How can I write a compact expression to handle this?