[SalesForce] Junction object in Salesforce

What kind of relation should a junction object have with it's parent objects?

What I know from Salesforce documentation:
The junction object should have master-detail relationships with the parent objects.

When I check the pricebookentry relationship with product and pricebook, I see this:

Both Product and Price Book are lookups in pricebookentry and pricebookentry is a junction object.

So, doesn't it contradict with the definition of junction object?

I'm confused. Am I missing something? Can I create a junction object using lookups too?

Best Answer

I disagree with the "common knowledge" on this issue. I have run into use-cases where using a Lookup relationship instead is appropriate. The junction object is a more flexible concept than people give it credit for. I agree that the following are preferable:

Junction should only relate to two objects
Junction should never be orphan

However, these requirements are not terribly difficult to satisfy without the use of Master-Detail relationships. For example a Validation Rule can count all the lookups and make sure you have exactly two.

A Concrete Example

Let's say you want to mimic polymorphism in your junction. Consider, for example, if I have one object that I want to relate to five others via many-to-many relationship. Do I create five separate true junctions or one junction-like object? There are valid arguments for each side, but to flat out reject the mock polymorphism because it uses Lookup instead of Master-Detail may not be an option in all orgs (sometimes you are limited to ten custom objects).

Related Solutions

[SalesForce] Using Product standard price in Custom Object

Unit Price, unless a custom field, is not a field available on the Product object. In order to achieve what I think you are after I think you would have to revert to code either as part of a custom controller or a trigger.

I think you would need to query the PricebookEntry object:

   Select p.UnitPrice, p.Product2.Name, p.Product2.Id, p.Product2Id, 
   p.Pricebook2.IsStandard, p.Pricebook2Id From PricebookEntry p
   where p.Pricebook2.IsStandard = true
   and p.Product2Id = :someProductId

Unfortunately, you can't create a lookup directly to PricebookEntry as it's one of those 'funny' objects.

[SalesForce] UseStandardPrice field when import PricebookEntry

Conceptually, there is one Standard Pricebook and there are many custom Pricebooks. This allows you to do the following:

For SKU xyz, the standard pricebook price could be $10.00
For the same SKU xyz, on the pricebook called Commercial, the price is $10.00
For the same SKU xyz, on the pricebook called US Government, the price is only $8.00

When you create a pricebookEntry for the junction between Product2 and Standard Pricebook, set useStandardPricebook to false. All pricebookEntries on standard Pricebook have useStandardPrice = false

When you create a pricebookEntry for the junction between Product2 xyz and Pricebook US Government, set useStandardPricebook to false and set unitPrice to 8.00.

On custom pricebook called 'Commercial' where SKU xyz is $10.00, then when you create a pricebookEntry for the junction between Product2 xyz and Pricebook Commercial, set useStandardPricebook to true and set unitPrice to 10.00.

In effect, your updates to PricebookEntry are mimicing the SFDC Force.com user interface where you define standard pricebook prices for a Product and then, if you use custom pricebooks, you can choose to use the standard price or override the standard price, just for that pricebook.

Don't forget that all pricebook entries must be inserted against the Standard pricebook before you can insert pricebookEntries on custom pricebooks.

Best Answer

Related Solutions

[SalesForce] Using Product standard price in Custom Object

[SalesForce] UseStandardPrice field when import PricebookEntry

Related Topic