I have a custom object called Server_Order__c used in my customer portal which is then mirrored to my Opportunities, I would like to also copy over attachments to the relavent Opportunity.

How the attachment can be linked to the right Opportunity is by getting the Opportunity__c value from Service_Orders__c object.

Edit:
Due to the way SF works, attachment are uploaded to their own object and justhave reference the parent object which means the record is not updated hence my code will not work as desired. What I would like to know is how can I have any attachments uploaded to my Service Order object, they should be also copied to the relevant Opportunity. The mirrored opportunity (ID) is referenced in my Service Order as Opportunity__c.


Here is my apex trigger as of now, but it does not seem to work.

    trigger CopyAttachments on Service_Order__c (after update) {
    
     Attachment[] attList = [select id, name, body from Attachment where ParentId = :Trigger.new[0].name];
     Attachment[] insertAttList = new Attachment[]{};
    
             for(Attachment a: attList)
             {
                   Attachment att = new Attachment(name = a.name, body = a.body, parentid = Trigger.new[0].Opportunity__c);
                   insertAttList.add(att);
             }
    
           if(insertAttList.size() > 0)
           {
                insert insertAttList;
           }