Hello,

Just a little background on my situation, I'm a new Admin/Developer for Salesforce, my company recently started using Salesforce and I'm trying to fulfill all the needs as they come. I have NOT had the time to go through any formal trainning on Salesforce Admin/Dev, I do have .Net programming experience though.

What I need help with is an issue with downloading Files/Attachments from an Opportunity, currently we have users that will upload 5-15 PDF's to an Opportunity and a different user will need to download all the files to process them in another system. Currently I don't see any way to "Download All Files" so the users have been downloading them one at a time and when they have 5-10 different Opportunities like this it becomes a time consuming task.

I have been tasked with finding an efficent way to download all the files/attachments, to accomplish this task I was trying to access the attachments from Apex so I could work with them programmically. Currently I can't even get that to work, everything I try returns zero rows, so this is how I was trying to access those Files/Attachments. Again I am very new, so feel free to suggest better methods to accomplish this task! 

string opportunityId = '0018000000M34fSfdsfS';
List<Attachment> attList = [Select Id, Name FROM Attachment WHERE ParentId =: opportunityId];

I know the Opportunity has Files that I can view but still the query returns zero rows. I also tried some combinations of CombinedAttachments and ContentDocument but still struggling, any help would be greatly appreciated!