[SalesForce] view Contact opportunity role object

Well, you've probably figured out by now that Triggers aren't supported on OpportunityContactRole (OCR). And, when an OCR is CRUD'd, there is no trigger that fires on the Opportunity either.

There is an idea for this - https://success.salesforce.com/ideaview?id=08730000000BrdvAAC

I've seen three workarounds

• Run a scheduled batch apex job that sweeps the Opportunities (or Contacts) and looks at their OCR and compares them to previously-saved OCRs (saved in another child sobject or possibly as a hidden long text Opportunity/Contact field as serialized JSON)

• Create an 'on view' trigger for your standard Oppo page layout that compares the current OCR to some prior value of the OCR (saved as above). See http://www.soliantconsulting.com/blog/2012/08/view-triggers-salesforce-trigger-opportunity-contact-roles for the code. Advantage here is that feedback to user is near immediate, subject to only how long the future method takes to run (see code in link)

• Redo your Oppo page as a VF page with a custom component to add/delete/change OCRs. Your VF controller can then act on the before/after values and save in the Oppo/Contact.

I think it may be happening because of this section of code which initializes the conId to null and also has a break inside the if statement in the middle of the for loop. The conId will be null if not set to null anyway. I suggest you remove both the break; and leave the initialization as simply Id conId;. You may need to add a null check before adding values to your map at the end of the 1st major loop.

for(Account a: accList)
{ 
    Id conId=null;  <<== Remove the initalizion to null.
    if(a.contacts.size()>0)
    {
        //Get contact of recent LastActivityDate
        conId = a.contacts.get(0).Id;
        //Get contact where From A2Z TRUE and overwrite above contact id if found
        for(Contact c: a.contacts)
        {
            if(c.From_A2Z__c==true)
            {
                conId=c.Id;
                break;  <<== remove this break
            }
        }
    }
    // regardless, may need to add if(conId != null){
    mapOfAccIdNConId.put(a.Id,conId);
    // }
}

With that having been said, you may have other workflow in your org that's creating the OCR for you automatically and your trigger may not be needed at all. Since you've also not included the remainder of your code that might tell us what else could be contributing to your issues, there's nothing more I can tell you.