[SalesForce] Roll-up summary OR workflow

I have a parent-and-child-object scenario. The parent will have a TOTAL field and the child a VALUE field. I want to show a total of all child VALUES on the parent.

I can either do that with a Master/Detail and use a roll-up summary field or a Lookup and a workflow or trigger to do the calculations I guess.

The reason I'm considering workflow / Apex trigger is that I may want to control the security of both objects independently. However, I realise that using workflow / trigger I will need to recalculate the total each time, meaning I have to grab all children, manually code the calculations, etc…

What are the pros / cons of both approaches?

Best Answer

The pros and cons list for rollup summary vs trigger is pretty short. In fact, you've taken care of most of the pros and cons of using a rollup summary in your question.

Rollup Summary:

Pros:

Standard behavior provided by Salesforce, well documented and understood
Doesn't require a trigger

Cons:

Requires a Master-Detail relationship
Has some restrictions on which fields can be aggregated (e.g. Can't roll up a formula field on the Detail object if it is a cross-object formula)
Limited to 25 rollup summary fields on a single object (prior to Winter '16, this limit was 10, and you could call Salesforce Support to get it increased)

Rollup via Trigger:

Pros:

Can work with lookup relationships (or a text field holding a parent record Id if you can't make a lookup to the object. OpportunityLineItem comes to mind)
Can work with more than 25 fields
Can work with a wider range of fields (provided you can write the summarization logic)

Cons:

Requires a trigger (and some test coverage)
Requires at least one query
Rollup must be explicitly coded

There are a few different ways to accomplish a rollup via trigger

Keep a map for each field you want to roll-up. Iterate over child records, and update the maps as you go
Use Aggregate functions in the SOQL query to do the rollup. [SELECT SUM(Field1__c) FROM myCustomObject__c]
Install Andrew Fawcett's Declarative Rollup Summary tool

Personally, when I need to use a trigger to do a rollup, I favor using a SOQL query to do the heavy lifting. Doing it via SOQL takes care of most of the null checks, and saves writing the same boilerplate summing logic over and over.

The declarative rollup summary tool is probably the best choice for most people outside of using a standard rollup summary field. I haven't used it myself, and don't know how well it would play with various trigger frameworks.

Conclusion:

In your case, the decision probably comes down to the question of how likely you are to need to manage the security of both objects independently.

If you will need to manage them independently, or think it's quite likely you will need to someday, go with a trigger rollup (looking at the declarative rollup summary tool first). Putting your two objects into a Master-Detail relationship would leave you with a technical debt that would be hard to resolve.

If their security can be managed together, and it doesn't look like that will ever change, go with the standard rollup via Master-Detail relationship.

Related Solutions

[SalesForce] Roll up summary trigger for formula field

As you were getting a null pointer issue from this trigger, without knowing the line which threw this error, my guess is that you were inserting a Recipt__c object and the trigger.oldMap.get(rec.id).Received__c statement in your code would have thrown a null pointer exception. The oldMap variable is only available in update and delete triggers therefore when inserting a Receipt an exception was thrown. Documentation on trigger context variables can be found in the following link http://www.salesforce.com/us/developer/docs/apexcode/Content/apex_triggers_context_variables.htm

To fix this issue you could implement something like the following

for (Recipt__c rec : trigger.new )
    {
        if(rec.Opportunity__c != null)
        {
            //if the trigger is insert there will be no trigger.oldMap
            //if inserting the object the Opp rollup will be required therefore add the Id to the list.
            if(trigger.isInsert)
            {
                oppId.add(rec.Opportunity__c);
            } //if updating a record check to see if the two values to rollup have changed, if so add Opp to the list
            else if (trigger.isUpdate && (rec.Received__c != trigger.oldMap.get(rec.id).Received__c || rec.Due_Amount__c != trigger.oldMap.get(rec.id).Due_Amount__c ))
            {
                oppId.add(rec.Opportunity__c);
            }
        }
    }

in place of

for (Recipt__c rec : trigger.new ){
    if(rec.Opportunity__c != null && (trigger.isInsert ||  trigger.isUpdate|| trigger.isUnDelete || trigger.isDelete|| rec.Received__c != trigger.oldMap.get(rec.id).Received__c || rec.Due_Amount__c != trigger.oldMap.get(rec.id).Due_Amount__c ))oppId.add(rec.Opportunity__c);


}

[SalesForce] Update Trigger on Parent record on Roll-up summary field when child records are inserted or deleted

The update triggers on parent will be fire .200 child records are processed at a time when you delete 1000 records .This means there will be 5 chunks .Lets say 200 child belongs to 10 parent records ,trigger.new will have 10 parent records .

The trigger on Parent would run for update case .In your case you are deleting or inserting and that should trigger update triggers on parent records .

To confirm this behavior just did a quick experiment

1.Create a parent object and a child object .Associate them via master detail .

2.Create a number field on the child record .

3.Create a roll up summary field on the parent record summing the number field that's created in previous field

4.Create a trigger on the parent record like below

trigger triggerSpeaker on Parent__c (before update) {
  if(trigger.isbefore && trigger.isupdate){
    for(Parent__c sp:trigger.old ){
      sp.addError('You cannot update me');
    }
  }
 }

5.Delete or insert the data into child objects via data loader or developer console.You should see the add error indicating triggers fire

Best Answer

Related Solutions

[SalesForce] Roll up summary trigger for formula field

[SalesForce] Update Trigger on Parent record on Roll-up summary field when child records are inserted or deleted

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