Hello,

I have a trigger that fires on OpportunityLineItem and updates the associated Opportunity with a count of Opportuity Products by grouping and a sum of their TotalPrice by grouping.  I have a custom field on the Opportunity called Coach_Count__c (gives number of products that have Prod_Grp__c = "Coaching") and one called Coach_Dol__c (sums the TotalPrice field for all products that have Prod_Grp__c = "Coaching").  I also created a custom field in the Opportunity Product called Count__c, which is simply a "1" and I sum that to get the count, and I created another field called Total_Price__c which is a formula field that has the value of TotalPrice from the Opportunity Product.  My trigger works as expected when adding or editing Products as both the Coach_Count__c and Coach_Dol__c fields get updated.  The Coach_Count__c field also updates properly when deleting products.  However, the Coach_Dol__c fails to update when there are multiple products where Prod_Grp__c = "Coaching" and will only update when there are none left.  Below is the Trigger.Old section of my trigger.  Can anyone tell me why I cannot get it to update when there are multiple products that have the same Prod_Grp__c value?

Map<id,id> M= new map<id,id>();
For(OpportunityLineItem deliv2:trigger.old){

oppIds.add(deliv2.OpportunityId);
m.put(deliv2.opportunityid,deliv2.id);
}
opp = [SELECT Id, Coach_Dol__c,Coach_Count__c
FROM Opportunity
WHERE Id IN:oppIds];

for(Opportunity o: opp){
if(trigger.oldmap.get(M.get(o.id)).Prod_Grp__c=='Coaching')
o.Coach_Count__c-=trigger.oldmap.get(M.get(o.id)).Count__c;

else if(trigger.oldmap.get(M.get(o.id)).Prod_Grp__c=='Coaching')
o.Coach_Dol__c-=trigger.oldmap.get(M.get(o.id)).Tot_Price__c;

}
Update (Opp);