Hello,

The business requirement is to have a lookup relation ship between a Contract and Opportunity. A field on the opportunity must get the SUM of a custom field on the Contracts which belong to the opportunity.

On mass update, I get an error "first error: UNABLE_TO_LOCK_ROW, unable to obtain exclusive access to this record"

After I lock the Account record, I get "First error: Record Currently Unavailable: The record you are attempting to edit, or one of its related records, is currently being modified by another user. Please try again."
 

public class contractRollUpCLASS {
    @future
    public static void calculate(Set<Id> recordIds) {
  
    List<Contract> contrList = [SELECT Id, AccountId, Renewal_Opportunity__c FROM Contract WHERE Id IN : recordIds];
    Set<Id> oppIds = new Set<Id>();
    Set<Id> accIds = new Set<Id>();
    
    for(Contract con : contrList) {
        oppIds.add(con.Renewal_Opportunity__c);
        accIds.add(con.AccountId);
        
    }
        
//lock the account
    List<Account> accList = [SELECT Id FROM Account WHERE Id IN : accIds FOR UPDATE];
    
    
    //Map will contain one Opportunity Id to one sum value.
    map<Id, Double> OpportunityMap = new Map<Id,Double>();
    
    List<Opportunity> oppsToUpdate = new List<Opportunity>();
    
    //aggregate result.
    for(AggregateResult q : [SELECT Renewal_Opportunity__c, SUM(Latest_PD_Renewal_Amount__c) sumLatest FROM Contract WHERE Renewal_Opportunity__c IN : oppIds AND Latest_PD_Renewal_Amount__c != null GROUP BY Renewal_Opportunity__c]) {
  
        OpportunityMap.put((Id)q.get('Renewal_Opportunity__c'),(Double)q.get('sumLatest'));
    }
    
    for(Opportunity opp : [SELECT Id, Annual_Maintenance_Value__c, AccountId FROM Opportunity WHERE Id IN : oppIds]) {
 
        Double sumLatestPD = OpportunityMap.get(opp.Id);
        opp.Annual_Maintenance_Value__c = sumLatestPD;
        oppsToUpdate.add(opp);     
    }    

        update oppsToUpdate;   

    }
}

Any ideas how I can bypass this issue?
Thanks,

Angel