[SalesForce] Trigger, count related records

Here is the case I am working with now:

There is a Custom_Object__c linked to Case object via lookup field (Custom_Object__c is a parent). After a new case is created, Case_Count__c field should be updated on Custom_Object__c with the number of cases tied to that object. Here is the sample code I wrote that adds +1 on Case_Count__c field every time a new case is inserted(works fine):

trigger CaseCount on Case (after insert) {
List<Case> lstCase = [select id, Custom_object_lookup__c, Type from Case where id in: trigger.newmap.keyset()];
set<Id> custObjId = new set<Id>(); 
for(Case cs: lstCase){
    if(cs.Custom_object_lookup__c != null) {
        custObjId.add(cs.Custom_object_lookup__c);   

    }

    if(custObjId != null && custObjId.size() > 0) { 

    List<Custom_object__c> lstCustomObject= [select id, Case_Count__c from Custom_object__c where id in: custObjId ]; 


    if(lstCustomObject.size() > 0){
        for(Custom_object__c custObj: lstCustomObject){
            System.debug('Case count before update: ' + custObj.Case_Count__c);
            custObj.Case_Count__c += 1;
            System.debug('Case count after update: ' + custObj.Case_Count__c);

        }
        }

      update lstCustomObject;

    }

}}

Question: What would be correct way/approach to query all the cases related to Custom_object__c and update the Case_count__c field accordingly?

Best Answer

Rather than coding your own solution, I'd recommend using DLRS to do the work for you. It is a free tool and very powerful. It will let you rollup counts as part of inserts, and also run rollups on a schedule or adhoc. It will also solve some problems that you haven't addressed in your code such as deletes of cases or changes to the custom object lookup field.

If you want to write your own code, you can use an aggregate query to get a count of cases this way:

SELECT Custom_object_lookup__c, Count(Id) 
FROM Case 
GROUP BY Custom_object_lookup__c

Related Solutions

[SalesForce] Trigger to copy child object picklist values to parent object separated by comma

The code you have shared will not at all compile.

use close brace here for (Opportunity childObj : Trigger.new)
use childObj.AccountId instead of childObj.Account to access AccountId
When you use relationship query be sure to use Opportunities instead of Opportunity.
You should put Opportunity's Opp_Location__c into a List. Then use String.join() to add those with comma delimited.
And finally update accounts.

Trigger

trigger UpdateAmount on Opportunity (after insert, after update) { 
  Map<ID, Account > parentOpps = new Map<ID, Account>(); 
  Set<Id> listIds = new Set<Id>();

  for (Opportunity childObj : Trigger.new) {
    listIds.add(childObj.AccountId);
  }

  parentOpps = new Map<Id, Account>([SELECT id, Location_Type__c ,
                                        (SELECT ID, Opp_Location__c  FROM Opportunities) 
                                    FROM Account WHERE ID IN :listIds]);

  List<Account> lstAccount = new List<Account>();

  for(Account acct:parentOpps.values())
  {  
      List<String> strType = new List<String>();
      for(Opportunity oppty:acct.Opportunities)
      {
          strType.add(oppty.Opp_Location__c);
      }
      acct.Location_Type__c = String.join(strType,',');

  }

  update parentOpps.values();
}

Trigger to update parent record field from child

The issue is in the below line .

acc.Closed_Cases__c+=noOfCases;

If the value of Closed_Cases__c field is null then you are adding 1 to the null which gives null pointer exception. Instead of that you can make the default value of the field to 0 or replace that line with the below line.

      if(acc.Closed_Cases__c!=null){
        acc.Closed_Cases__c+=noOfCases;
        }
        acc.Closed_Cases__c=1;

Which means if the value is null and we are closing the case this will populate to 1 if it is not null then it will increment by 1.

Even the above code may not work as expected because the trigger should work for the existing closed cases as well. so the logic should be counting the number of closed cases and populating the value as below.

if(AccIDs != null && AccIDs.size() > 0){
        List<Account> lstAccount = [select id, Closed_Cases__c , (select id from Cases where status = 'Closed') from Account where id in: AccIDs];
        if(lstAccount.size() > 0){
            for(Account acc: lstAccount){
                acc.Closed_Cases__c  = acc.Cases.size();
            }
            
            update lstAccount;
        }
    }

Best Answer

Related Solutions

[SalesForce] Trigger to copy child object picklist values to parent object separated by comma

Trigger to update parent record field from child

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