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ekorzekorz 

Trigger using a reference field

I have custom object called "Locations" from which my team can create Opportunities.  "Locations" contains a "LocationDescription__c" field that's usually full of great notes, so I'd like to build a trigger to copy those notes into my Opportunity.Description field.  Simple enough right?

 

I expect that I have to build a Map<>, maybe do a SOQL query to store the related object data into the trigger, but I'm very new to this.

Here's my code, which stores a null value into Opportunity.Description when it's executed:

 

 

trigger OppUdate on Opportunity(before insert, before update) {
            
   for(Opportunity opp : Trigger.new){
           if (opp.Description == null) {
          opp.Description = opp.Location__r.LocationDescription__c;
         }
       }
}

 

 

Thanks in advance!

Best Answer chosen by Admin (Salesforce Developers) 
sfdcfoxsfdcfox

You're perfectly right. Here's how it goes:

 

trigger OppUpdate on Opportunity(before insert, before update) {
  Map<Id,Location__c> locations = new Map<Id,Location__c>();
  for(Opportunity record:Trigger.new)
    locations.put(record.Location__c,null);
  locations.putAll([SELECT Id,LocationDescription__c FROM Location__c WHERE Id IN :locations.keySet()]);
  for(Opportunity record:Trigger.new)
    if(record.Location__c!=null)
      opp.Description=locations.get(record.Location__c).LocationDescription__c;
}

Note, Location__c is the presumed data type name for the lookup's data type; adjust as necessary.

 

Brackets are omitted for brevity, but please feel free to include them if necessary.

All Answers

sfdcfoxsfdcfox

You're perfectly right. Here's how it goes:

 

trigger OppUpdate on Opportunity(before insert, before update) {
  Map<Id,Location__c> locations = new Map<Id,Location__c>();
  for(Opportunity record:Trigger.new)
    locations.put(record.Location__c,null);
  locations.putAll([SELECT Id,LocationDescription__c FROM Location__c WHERE Id IN :locations.keySet()]);
  for(Opportunity record:Trigger.new)
    if(record.Location__c!=null)
      opp.Description=locations.get(record.Location__c).LocationDescription__c;
}

Note, Location__c is the presumed data type name for the lookup's data type; adjust as necessary.

 

Brackets are omitted for brevity, but please feel free to include them if necessary.

This was selected as the best answer
izayizay

You could also have a formula field in the opportunity pointing to the location description: Location__r.LocationDescription__c

 

You can also pass this value to the opportunity in the URL using a custom button: *Change code in red with the id of the location field in opportunity

/006/e?retURL=%2F{!Location__c.Id}&ent=Opportunity&&opp4={!Account.Id}&opp14={!Location__c.Description__c}&CF00NZ0000000Y2DK={!Location__c.Name}&CF00NZ0000000Y2DK_lkid={!Location__c.Id}

 

Hope this helps!
ekorzekorz

Thanks, that's the stuff!  I edited my post a tiny bit so here's your code updated with those changes too (for posterity):

 

 

trigger OppUpdate on Opportunity(before insert, before update) {
  Map<Id,Location__c> locations = new Map<Id,Location__c>();
  for(Opportunity record:Trigger.new)
    locations.put(record.Location__c,null);
  locations.putAll([SELECT Id,LocationDescription__c FROM Location__c WHERE Id IN :locations.keySet()]);
  for(Opportunity record:Trigger.new)
    if(record.Description == null)
      record.Description = locations.get(record.Location__c).LocationDescription__c;
}
sfdcfoxsfdcfox
Remember to check if record.Location__c is not null, or you will receive an error. You should update it to:

if(string.isblank(record.description)&&record.location__c!=null)
ekorzekorz

Izay, you're right, that a formual field would actually solve this problem too, but I built a whole bunch of formula fields on this object already and I am running out references.  I learned about the magical power of formula fields early on, and, well, when you only have a hammer,  every problem looks like a nail right?