[SalesForce] Difference between a self relationship and Lookup relationship

With Self relationship you can reference the same object, at the same time you can create a lookup relationship and still refer to the same object. So when do you call a relationship as self vs lookup. ( I know using look up we can reference other object), but at the same time you can reference the same object as well.

So can someone please clarify when do you say a relationship is lookup vs self?

Best Answer

There are only technically two types of relationships between objects in Salesforce, master-detail and lookup. Though in reality when coding and in the UI you'll find both have some common behaviours and ways in which they can be used.

So Salesforce does not technically require you to do anything different regardless if your lookup references another object or itself, both are the same field type, lookup. So the difference is more the use case your using the field for than it's type. Note that the Standard object Account uses self references to implement Account hierarchies, parent and child relationship.

This topic in the documentation Relationships Among Objects is a good place to start reading more, and i noticed also covers a cool use case of master-detail relationships relating to many-to-many relationships. Hopefully this sheds a bit more light on the topic for you, but if you need more feel free to explain a little more in your question about your use case.

Extract from the above linked help topic...

Relationships associate objects with other objects. For example, a relationship can link a custom object to standard object in a related list, such as linking a custom object called Bugs to cases to track product defects associated with customer cases. To view the parent and child relationships among standard objects, see the ERD diagrams in Data Model.

Related Solutions

[SalesForce] Lookup Relationship question

The relationship fields on Activity aren't actually Lookups, but polymorphic relationship fields. This is a special field type that the platform uses when a child record can have a relationship to more than one type of Parent. They aren't available as a field type to Salesforce users when defining new relationships in the database but they do show up on a few Standard objects.

They behave more like Master/Detail relationship fields when it comes to parent deletion.

[SalesForce] How to delete child object in Lookup relationship

If its a lookup you will need a simple trigger to do this in real time

trigger onParentObjectDelete on CustomObject__c (before delete){
List<Id> idsToQuery = new List<Id>{};
for(CustomObject__c a: Trigger.old){
    idsToQuery.add(a.id);
 }

//query all child records where parent ids were deleted
ChildObject__c[] objsToDelete = [select id from ChildObject__c where ParentId__c IN :idsToQuery];

delete objsToDelete; //perform delete statement
}

This is if you are planning to do a real time delete .Also in this case be sure to check with business what if someone undeletes a record from the bin.May be a trigger to handle this as well

Also if you don't need a real time delete ,a batch process to fetch orphaned childs(ParentId is null) and delete .

Best Answer

Related Solutions

[SalesForce] Lookup Relationship question

[SalesForce] How to delete child object in Lookup relationship

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