Object relationships are a special field type that connects two objects together.Let’s think about a standard object like Account. If a sales rep opens an account, they’ve probably been talking to a few people at that account’s company.
They’ve probably made contacts like executives or IT managers and stored those contacts’ information in Salesforce. It makes sense, then, that there should be a relationship between the Account object and the Contact object. And there is!
When you look at an account record in Salesforce, you can see that there’s a section for contacts on the Related tab. You can also see that there’s a button that lets you quickly add a contact to an account.
The Account to Contact relationship is an example of a standard relationship in Salesforce. But just like objects and fields, you can build custom relationships as well.
The different kinds of relationships you can create in Salesforce. There are two main types of object relationships: lookup and master-detail.
In our Account to Contact example above, the relationship between the two objects is a lookup relationship. A lookup relationship essentially links two objects together so that you can “look up” one object from the related items on another object.
Lookup relationships can be one-to-one or one-to-many. The Account to Contact relationship is one-to-many because a single account can have many related contacts. For our DreamHouse scenario, you could create a one-to-one relationship between the Property object and a Home Seller object.
One to Many relationship Sample Diagram
While lookup relationships are fairly casual, master-detail relationships are a bit tighter. In this type of relationship, one object is the master and another is the detail. The master object controls certain behaviors of the detail object, like who can view the detail’s data.
For example, let’s say the owner of a property wanted to take their home off the market. DreamHouse wouldn’t want to keep any offers made on that property. With a master-detail relationship between Property and Offer, you can delete the property and all its associated offers from your system.
Master-detail relationships can be used to model many-to-many relationships between any two objects. A many-to-many relationship allows each record of one object to be linked to multiple records from another object and vice versa.
A sample diagram of Many-to-Many Relationship
To start, create a custom object called Favorite with an Auto-Numbered name field. If you need a reminder on how to create objects, check the previous unit.
We’re going to create two custom relationship fields on the Favorite object. First, let’s create a lookup relationship that lists the users who favorite a property.
Now, we’re going to create a second relationship field. We want a master-detail relationship where Property is the master and Favorite is the detail.