After delete trigger failing during bulk delete

Question

I have a trigger that counts the number of child records by type and adds that to the parent. Each type has a field on the parent where the count is added. The update part of the trigger works fine during bulk uploads of child records. The delete works when child records are deleted one at a time. The problem is that the trigger times out when I try to delete more than 1.

I get the following error.

ERROR: System.DmlException: Delete failed. First exception on row 0 with ! id a0s1U000000v1SyQAI; first error: CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY, ! CMRules.pickListCount: execution of AfterDelete ! ! caused by: System.ListException: Duplicate id in list: a1N1U000001kDV6UAM

Any help would be appreciated! Thanks!

if(trigger.isDelete){

Map<Id,List<wbsendit__Campaign_Activity__c>> mapsentList = new 
Map<Id,List<wbsendit__Campaign_Activity__c>>();                        
List<Id> summaryList = new List<Id>();
Set<id> summarySet = new set<Id>();
list<wbsendit__Campaign_Activity__c> summaryActivityList = new 
list<wbsendit__Campaign_Activity__c>();    

for(wbsendit__Campaign_Activity__c tc : trigger.Old){
    if(tc.Email_Tracking_Summary__c!=null){
        wbsendit__Campaign_Activity__c tempRecords = new 
wbsendit__Campaign_Activity__c(id = tc.ID, Email_Tracking_Summary__c = 
tc.Email_Tracking_Summary__c, wbsendit__Activity__c = 
tc.wbsendit__Activity__c);
        summaryActivityList.add(tempRecords);
        summaryList.add(tc.Email_Tracking_Summary__c);
        summarySet.add(tc.Email_Tracking_Summary__c);                                
        mapsentList.put(tc.Id,summaryActivityList);                                
    }
}

List<Email_Tracking_Summary__c> sentList   = new 
List<Email_Tracking_Summary__c>();
List<Email_Tracking_Summary__c> openList   = new 
List<Email_Tracking_Summary__c>();
List<Email_Tracking_Summary__c> clickList  = new 
List<Email_Tracking_Summary__c>();
List<Email_Tracking_Summary__c> unsubList  = new 
List<Email_Tracking_Summary__c>();
List<Email_Tracking_Summary__c> bounceList = new 
List<Email_Tracking_Summary__c>();


for(Email_Tracking_Summary__c c : [SELECT id, Sent__c, Opened__c, Clicked__c, 
Unsubscribed__c, Bounced__c FROM Email_Tracking_Summary__c WHERE id in: 
summarySet]){
    for(List<wbsendit__Campaign_Activity__c> idList : mapsentList.values()){
        for(wbsendit__Campaign_Activity__c idVal : idList){

// begin populating lists to update counts
            // list for open sent                                    
            if(c.Id == idVal.Email_Tracking_Summary__c && 
idval.wbsendit__Activity__c == 'Sent'){
                c.Sent__c = c.Sent__c - 1;
                sentList.add(c);
                }

            // list for open deletes 
            else if(c.Id == idVal.Email_Tracking_Summary__c && 
idval.wbsendit__Activity__c == 'Opened'){
                c.Opened__c = c.Opened__c - 1;
                openList.add(c);
                }

            // List for clicks
            else if(c.Id == idVal.Email_Tracking_Summary__c && 
idval.wbsendit__Activity__c == 'Clicked'){
                c.Clicked__c = c.Clicked__c - 1;
                clickList.add(c);
                }

            // List for unsub list
            else if(c.Id == idVal.Email_Tracking_Summary__c && 
idval.wbsendit__Activity__c == 'Unsubscribed'){
                c.Unsubscribed__c = c.Unsubscribed__c - 1;
                unsubList.add(c);
                }

            // List for unsub deletes
            else if(c.Id == idVal.Email_Tracking_Summary__c && 
idval.wbsendit__Activity__c == 'Unsubscribed'){
                c.Unsubscribed__c = c.Unsubscribed__c - 1;
                unsubList.add(c);
                }

            // List for bounced deletes
            else if(c.Id == idVal.Email_Tracking_Summary__c && 
idval.wbsendit__Activity__c == 'Bounced'){
                c.Bounced__c = c.Bounced__c - 1;
                bounceList.add(c);
                }
            }                                
        }
    }
    update sentList;
    update openList;
    update clickList;
    update unsubList;
    update bounceList;
}

Answer 1

Your triple nesting of loops is likely to consume a large amount of CPU time needlessly, and you may want to look at how to simplify the structure. But typically you can get around this type of error by simply using a Map rather than a List.

Map<Id, SObject> records = new Map<Id, SObject>();
// put record in by Id as many times as you like
update records.values();