How can I create rollup Summary field in Account Object with Opportunity Amount using Triggers?

Hi Aman,

First make a field on account object with name "OppAmount" and then use this code:

#Trigger
trigger calAmount on Opportunity (after insert, after update, after delete) {
Map<Id, List<Opportunity>> acctIdOpptyListMap = new Map<Id, List<Opportunity>>();
Set<Id> acctIds = new Set<Id>();
List<Opportunity> opptyList = new List<Opportunity>();
if(trigger.isUpdate || trigger.isInsert){
for(Opportunity oppty : trigger.New){
if(oppty.AccountId != null){
acctIds.add(oppty.AccountId);
}
}
}
if(trigger.isDelete){
for(Opportunity oppty : trigger.old){
if(oppty.AccountId != null){
acctIds.add(oppty.AccountId);
}
}
}
if(acctIds.size() > 0){
opptyList = [SELECT Amount, AccountId FROM Opportunity WHERE AccountId IN : acctIds];
for(Opportunity oppty : opptyList){
if(!acctIdOpptyListMap.containsKey(oppty.AccountId)){
acctIdOpptyListMap.put(oppty.AccountId, new List<Opportunity>());
}
acctIdOpptyListMap.get(oppty.AccountId).add(oppty);
}
List<Account> acctList = new List<Account>();
acctList = [SELECT OppAmount__c FROM Account WHERE Id IN: acctIds];
for(Account acct : acctList){
List<Opportunity> tempOpptyList = new List<Opportunity>();
tempOpptyList = acctIdOpptyListMap.get(acct.Id);
Double OppAmount = 0;
for(Opportunity oppty : tempOpptyList){
if(oppty.Amount != null){
OppAmount += oppty.Amount;
}
}
acct.OppAmount__c = OppAmount;
}
update acctList;
}
}

Hope this may help u.

Hi @shaharyar and @parul-2 the code is very helpful however, it also calculates Closed Lost Opportunities. How do I filter it and only calculate the Opportunities that are in Closed Won and Invoice Sent? Thank you.