[SalesForce] Trigger to autopopulate a lookup field via related record

I have a custom object in salesforce. Every record has many fields. One is a lookup field in which we select an opportunity from lookup. What we want is another lookup field: Account__c which has to be automatically populated with account name of that respective opportunity.

In the code below, "After insert" is working but before update is not working properly.

 trigger trigger_name on object__c (after insert, before update) {

    List<object__c> listOfSfdcRecords  =[SELECT Opportunity__r.AccountId,Opportunity__r.Account.Name FROM object__c WHERE ID IN :trigger.newMap.keySet()];
    Map<String, Id> myMap = new Map<String, Id>(); 
    for(object__c eachRec : listOfSfdcRecords){
        System.debug(listOfSfdcRecords);          
        myMap.put(eachRec.Id, eachRec.Opportunity__r.AccountId);
    }
    if(trigger.isAfter){
        List <object__c> updateList = new List <object__c>();
        for(object__c eachSfdc: listOfSfdcRecords){
            System.debug(eachSfdc.Opportunity__r.AccountId);
            object__c sfdc = new object__c(Id = eachSfdc.Id);
            sfdc.Test_Account__c = eachSfdc.Opportunity__r.AccountId;
            updateList.add(sfdc);
        }
        update updateList;
    }
    if(trigger.isBefore){
        for(object__c eachSfdc: trigger.new){
            //System.debug('before update'+eachSfdc.Opportunity__r.AccountId);
            System.debug('b4 update'+myMap.get(eachSfdc.id));
            eachSfdc.Test_Account__c = myMap.get(eachSfdc.id);
        }
    }

}

Best Answer

You can do something like this. Basically you would need to get the opportunities of all the records that you're inserting / updating, get the associated accounts and then set the account values in the customOject's account__c field.

trigger autoPopulateTrigger on customObject__c (before insert, before update){

    //get the oppotyunity Id's and store it in a set.
    set<Id> opptyIdSet = new set<Id>();
    for(customObject__c co: trigger.new){
        if(co.opportuntiy__c != null){
            opptyIdSet.add(co.opportunity__c);
        }
    }

    //query the opportunity records and get the associated accounts.
    map<id, opportunity> opptyMap = new map<id, opportunity>{[SELECT id, accountid from opportunity where Id IN: opptyIdSet]};

    //update the account value based on the opportunity in the record.
    for(customObject__c co: trigger.new){
        if(opptyMap.containsKey(co.opportunity__c)){
            co.Account__c = opptyMap.get(co.opportunity__c).accountId;
        }       
    }

}

Related Solutions

[SalesForce] Trigger to match field in another object and populate a relationship lookup

The expression trigger.newMap.keyset() contains ID's of the records and not names. Therefore your query should look like [Select Id From InForceEW_invoice_c Where Id IN :trigger.newMap.keyset()]; which SHOULD return the targeted invoices.

This will NOT return any records again, since your trigger is on the receivable object and you're querying invoices with ID of an receivable.

What you need to do to get all invoices that match a name of a receivable in your trigger, is to create a set of names (based on the receivables in your trigger) and then query all invoices which have the same name as the receivables in the trigger and work with them.

Something like this:

// build a set of receivable names
Set <String> receivableNames = new Set <String> ();

for(InForceEW_Receivable_c theReceivable : trigger.New)
{
    receivableNames.add(theReceivable.Name);
}

// Map the invoice names and the actual invoice records based on the receivable names
Map <String, InForceEW_invoice_c> matchingInvoicesMap = new Map <String, InForceEW_invoice_c> ();

for (InForceEW_invoice_c invoice : [Select Id, Name From InForceEW_invoice_c Where Name IN :receivableNames])
{
    matchingInvoicesMap.put(invoice.Name, invoice);
}

List <InForceEW_Receivable_c> receivablesToUpdate = new List <InForceEW_Receivable_c> ();

// go through the records in the trigger again and check whether we have found a matching receivable and invoic
for(InForceEW_Receivable_c theReceivable : trigger.New)
{
    if (matchingInvoicesMap.get(theReceivable.Name) != null)
    {
        // we found a mathing one
        theReceivable.Invoice__c = matchingInvoicesMap.get(theReceivable.Name).Id;

        // add it to a separate list and update it
        receivablesToUpdate.add(theReceivable);
    }
} 

update receivablesToUpdate;

Now the updating of the receivables will cause the trigger to fire again and again leading to recursive trigger and result with an error. You need to implement some sort of functionality that will prevent this. I will leave that part on you as an exercise...

[SalesForce] Why Trigger.newMap in before Update event

New map, as the name suggests, is to provide access to the new values the records will take on during the DML operation.

You might want this in before events to perform some kind of validation, for example (pseudeocode):

for each record in trigger.old
  if record.field == 'A' && trigger.newMap.get(record.Id).field == 'C'
    error('You can not change field straight from A to C!');

Using newMap in a Before Update trigger will let you access the new field values, oldMap will provide you with the existing values. As you can see from the above, it's useful to have access to both so that you can take action as business logic dictates.

Best Answer

Related Solutions

[SalesForce] Trigger to match field in another object and populate a relationship lookup

[SalesForce] Why Trigger.newMap in before Update event

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