Apex Specialist Challenge 1 too Many DML Rows - salesforce

Question

I'm Working through this challenge and appear to have run into an issue i have not found a solution to (nor does it appear that anyone has posted a question on this specifically.)
looking at the log is pretty painful as any System.debug() lines appear to be dropped due to the size of the log being >18MB but it appears there are 40000 rows to be added. Having caved and looked at some of the other code dumps out there i dont see that anyone else looks to have had this issue or made any special arrangements with batching and as far as i can see i haven't done anything drastically different to them (but the subtlety is clearly more than enough to cause an issue).
So if anyone could have a look over this and give me a hint as to where/why i have gone wrong it would be a great help. I'm not looking for a link to a working code set to copy i'm hoping for some understanding as to where my approach is incorrect/causing issues
With my trigger
trigger MaintenanceRequest on Case ( after update) {
List<Case> closedCases = new List<Case>();
for (Case c : Trigger.New){
System.debug('Type :' + c.Type );
System.debug('Equals Repair: ' +c.Type.equalsIgnoreCase('Repair'));
System.debug('Equals Routine Maintenance: ' +c.Type.equalsIgnoreCase('Routine Maintenance'));
if (
(c.Type.equalsIgnoreCase('Repair') || c.Type.equalsIgnoreCase('Routine Maintenance'))
&& c.isClosed == true )
{
closedCases.add(c);
}
}
System.debug(closedCases.size() + ' cases were closed');
if(closedCases.size() > 0){
MaintenanceRequestHelper.createScheduledMaintainance(closedCases);
}
}
and helper
public with sharing class MaintenanceRequestHelper {
public MaintenanceRequestHelper() {
}
public static Map<Id,Integer> getMainainanceCycleForCases(){
List<AggregateResult> maintainTimes = [SELECT Maintenance_Request__c, MIN(Equipment__r.Maintenance_Cycle__c)cycle
FROM Equipment_Maintenance_Item__c
GROUP BY Maintenance_Request__c
];
System.debug(maintainTimes);
Map<Id,Integer> maintinTimeMap = new Map<Id,Integer>();
for( AggregateResult e : maintainTimes ){
maintinTimeMap.put((Id)e.get('Maintenance_Request__c'), ((Double)e.get('cycle')).intValue());
}
System.debug(maintinTimeMap);
return maintinTimeMap;
}
public static Map<Id,List<Id>> getMaintainanceItems(List<Case> closedCases){
// map maintainance_Request_ID, Equipment_Maintenance_Item__c
List<Equipment_Maintenance_Item__c> equipmentMaintainanceList = [SELECT Maintenance_Request__c,
Equipment__r.Id
FROM Equipment_Maintenance_Item__c
Where Maintenance_Request__c IN :closedCases];
Map<Id,List<Id>> maintainance_equipmentMap = new Map<Id, List<Id>>();
for (Equipment_Maintenance_Item__c e:equipmentMaintainanceList){
System.debug('Putting : '+ e.Maintenance_Request__c + ' : ' + e.Equipment__r.Id);
if(maintainance_equipmentMap.containsKey(e.Maintenance_Request__c)){
maintainance_equipmentMap.get(e.Maintenance_Request__c).add(e.Equipment__r.Id);
}else{
maintainance_equipmentMap.put(e.Maintenance_Request__c,new List<id>{e.Equipment__r.Id});
}
System.debug('Map now : '+ maintainance_equipmentMap);
}
System.debug('Returning: ' +maintainance_equipmentMap);
return maintainance_equipmentMap;
}
public static void createScheduledMaintainance(List<Case> closedCaseList) {
System.debug(closedCaseList.size() + ' Cases to create');
Map<Id,Integer> maintainTimeMap = getMainainanceCycleForCases();
Map<Id,List<Id>> maintainanceItems = getMaintainanceItems(closedCaseList); // map maintainance_Request_ID, Equipment_Maintenance_Item__c
List<Case> createNewCases = new List<Case>();
for(Case c : closedCaseList){
Case newCase = new Case();
newCase.Type = 'Routine Maintenance';
newCase.Status = 'New';
newCase.Vehicle__c = c.Vehicle__c;
newCase.Subject = c.Subject;
newCase.Date_Reported__c = Date.today();
newCase.Date_Due__c = Date.today() + maintainTimeMap.get(c.Id);
newCase.ProductId = c.ProductId;
createNewCases.add(newCase);
}
System.debug(createNewCases.size() +' to insert');
list<Equipment_Maintenance_Item__c> itemsListToinsert= new list<Equipment_Maintenance_Item__c>();
if(createNewCases.size()>0){
insert createNewCases;
for(Case ca : createNewCases){
for(Id key: maintainanceItems.keySet()){
List<Id> equipment = maintainanceItems.get(key);
for (Id e : equipment){
Equipment_Maintenance_Item__c newitem = new Equipment_Maintenance_Item__c();
newitem.Equipment__c=e;
newitem.Maintenance_Request__c= ca.Id;
itemsListToinsert.add(newitem);
}
}
}
}
System.debug('itemsListToinsert Size: ' +itemsListToinsert.size());
if (itemsListToinsert.size() >0){
insert itemsListToinsert; //<<<< ERROR TRIGGERS HERE and has ~40000 rows <<<<<
}
}
}

Answer 1

So, It seems i was over complicating the issue to an extent.
Having taken a break and walking through the problem again something just didnt sit right with this block of code.
if(createNewCases.size()>0){
insert createNewCases;
for(Case ca : createNewCases){
for(Id key: maintainanceItems.keySet()){
List<Id> equipment = maintainanceItems.get(key);
for (Id e : equipment){
Equipment_Maintenance_Item__c newitem = new Equipment_Maintenance_Item__c();
newitem.Equipment__c=e;
newitem.Maintenance_Request__c= ca.Id;
itemsListToinsert.add(newitem);
}
}
}
}
For -> For -> For -> create new Equipment_Maintenance_Item__c
With 0 checks to see if this new Equipment_Maintenance_Item__c was needed.
I ended up partly re-writing the class but the main change was re-working the section of code above to
List<Equipment_Maintenance_Item__c> equipmentMaintainanceList = [SELECT Maintenance_Request__c,
Equipment__r.Id
FROM Equipment_Maintenance_Item__c
Where Maintenance_Request__c IN :closedCaseList];
List<Equipment_Maintenance_Item__c> updatedEquipment = new List<Equipment_Maintenance_Item__c>();
for(Case closed : closedCaseList){
for(Equipment_Maintenance_Item__c eqip : equipmentMaintainanceList){
if (eqip.Maintenance_Request__c == closed.Id){
Equipment_Maintenance_Item__c e = eqip.clone(false, false, false, false);
e.Maintenance_Request__c = oldToNewMap.get(closed.Id).Id;
updatedEquipment.add(e);
}
}
}
if (updatedEquipment.size() > 0 ){
insert updatedEquipment;
}
For me the lesson is be very mindful of nested for loops when the outcome is going to come up against some hard and fast governor limits.