Hello,

I'm attempting to write my first trigger, so please bare with me while I explain.

The purpose of the trigger is to update some date fields based upon Events to show when the last meeting of various types was completed.  I've seen a few different threads on this site that I was able to pull some ideas from, but have been unable to figure out how to get one particular piece to work.  The issue comes when a meeting is Canceled or Rescheduled.  We want to keep these events in the system so we can refer back to them in the future (e.g. if a client says we haven't seen them in over a year, we can go back and see that they canceled on us twice), but we don't want these events to be reflected in the Last Meeting fields.

I believe I have it written correctly so far to update the field when a meeting is not Canceled or Rescheduled, I just don't know how to get it to work once the meeting is Canceled.  Theoretically, the field would already be updated with this meeting date, so I'd want the trigger to look back and pull the last meeting that was not canceled or rescheduled.  I have two ideas:

• Loop through the Account's Events and find the most recent one that was not canceled or rescheduled.  I'm thinking this would cause too many database queries and may throw an error.
• Create a second field (not visible on the Page Layout) that contains the last successful meeting date before this one.

Here's my code.  Be gentle, it's my first attempt!
 

trigger LastEventDate on Event (after insert, after update) 
{

	// The sets used to store the IDs of the Accounts or Contacts/Leads within an event that need to get updated
	Set <Id> whoIdSet = new Set <Id> ();
	Set <Id> whatIdSet = new Set <Id> ();

	for(Event e : trigger.net)
	{
		if(e.WhoId != null)
		{
			whoIdSet.add(e.WhoId);
		}
		
		if(e.WhatId != null && e.WhoId == null)
		{
			whatIdSet.add(e.WhatId);
		}
	}

	// Creates two maps in case whoId or whatId is not populated
	Map<ID, Contact> contactMap = new Map<ID, Contact>([select Id, AccountId from Contact Where Id in :whoIdSet]);
	Map<ID, Account> accountMap = new Map<ID, Account>([select Id, 	Last_Review_Meeting__c, Last_FP_Update__c, Last_IPS_Update__c, 	Last_Tax_Planning_Meeting__c, Last_Tax_Prep_Meeting__c from Account Where Id in :whatIdSet]);

	// The actual Accounts to save
	List <Accounts> Scheduled = new List <Accounts> ();
	List <Accounts> CancelledRescheduled = new List <Accounts> ();


	for(Event e : Trigger.new)
	{
		if(e.whoID != null && contactMap.containsKey(e.whoId))
		{
			//If meeting is scheduled as planned, set this meeting date to the appropriate Last Meeting Date field

			if(e.Status__c != "Canceled" && e.Status__c != "Re-Scheduled")
			{
				Contact c1 = contactMap.get(e.whoId);
				if(c1.AccountId != null)
				{
					Account a1 = c1.AccountId;
					Date d1 = Data.newInstance(e.StartDateTime.year(), e.StartDateTime.month(), e.StartDateTime.day());
					if(e.FSTR__Sub_Type__c == "Tax Preparation Meeting")
					{
						if(d1 > a1.Last_Tax_Prep_Meeting__c)
						{
							a1.Last_Tax_Prep_Meeting__c = d1;
						}
					}
					if(e.FSTR__Sub_Type__c == "Tax Planning Meeting" || Tax_Plan__c == TRUE)
					{
						if(d1 > a1.Last_Tax_Planning_Meeting__c)
						{
							a1.Last_Tax_Planning_Meeting__c = d1;
						}
					}
					if(e.FSTR__Sub_Type__c == "Client Review Meeting")
					{
						if(d1 > a1.Last_Review_Meeting__c)
						{
							a1.Last_Review_Meeting__c  = d1;
						}
					}
					if(e.Financial_Plan_Update__c == TRUE)
					{
						if(d1 > a1.Last_FP_Update__c)
						{
							a1.Last_FP_Update__c = d1;
						}
					}
					if(e.IPS_Updated__c == TRUE)
					{
						if(d1 > a1.Last_IPS_Update__c)
						{
							a1.Last_IPS_Update__c = d1;
						}
					}
					Scheduled.add (a1);
				}
			}
			
			// If meeting is canceled or rescheduled, set appropriate Last Meeting field to last meeting date that was not canceled or rescheduled

			if(e.Status__c == "Canceled" || e.Status__c == "Re-Scheduled")
			{
				
			}
		}
	}
}

Thanks in advance for any help!