[SalesForce] Relationship between account and contact

I checked 'Account Name' field in Contact object. It appeared as a Lookup(Account). But when I deleted that account, contact also got deleted which tells me it is a master-detail relation. Can anyone explain me the proper way to explain the relationship between account and contact?

Best Answer

There are four different kind of relationships in the force.com platform.

But I like to categorize them in a slightly different way than the help pages:

Lookup
Master-Detail
Hierarchy
Standard relationships

There are lot's of help topics and articles on Lookup and Master-Detail, such as the relationship overview and the relationship considerations topics in help. I don't like including Many-to-Many in this kind of discussion because, for all intents and purposes M:M is just an implementation of two M-D relationships (by strict reading of the docs), or possibly two lookup relationships or a mix of the two.

To dispense quickly with hierarchy relationships, these are a special lookup self-join relationship on the User object. Read up on those on your own. :-)

So let me talk about my own invented fourth category.

Standard Relationships

If we (salesforce.com) provide you with a relationship between two objects, that is a standard relationship. Not lookup, not master-detail. Why do I bother providing this fourth category? Because it is the easiest way to stop people trying to categorize them as either lookup or master-detail when they often share characteristics of both. When you approach working with any standard relationship the question you really need to answer is, "how does this standard relationship behave." Frequently standard relationships have characteristics that you just can't do with a custom relationship. Ever tried to make a custom relationship polymorphic? Go ahead...give it a try. You will fail. But there are many examples of polymorphic standard relationships.

I like to categorize these in their own separate place independent of lookup/master-detail. In fact, anything standard follows the same rule: it behaves exactly the way that salesforce.com wants it to behave to fit the particular purpose of that standard thing.

In my opinion, the Account-Contact relationship is a perfect justification for this fourth category: it is a little like lookup, a little like Master-Detail, but fundamentally behaves the way it does because we decided it should.

That might not be the "proper" way, as you ask, but it is the one that makes the most sense to me.

Related Solutions

[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 .

[SalesForce] Relationship between Account and Opportunity and Account and Contact

They are a unique category of fields commonly referred to as standard lookup fields. Unlike custom lookup fields, they have the generally have the "cascade deletion" property set to true, and unlike custom master-detail fields, they may have the "always required" property set to false. Also, these fields can restrict deletion of accounts when certain conditions are met. To learn their special properties, refer to Help for any particular field.

EDIT:

It's now possible to enable custom lookup cascade deletion, which has a similar behavior to how Accounts/Contacts, Account/Cases, and Account/Opportunities behave, but without the ability to restrict deletion when certain criteria are met. You can read this Knowledge Article for more information.

Best Answer

Related Solutions

[SalesForce] How to delete child object in Lookup relationship

[SalesForce] Relationship between Account and Opportunity and Account and Contact

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