No single data in Salesforce is virtually alone. Vast amounts of data in your Salesforce platform are often interrelated business concepts, and can be linked together by several connected objects. Relationships are then built among these connected objects in order for them to perform their best job in keeping data available and updated for all your business needs.
You can create three main relationship types in Salesforce. Among these relationships is the Many-to-Many Relationship. To facilitate the creation of such a relationship, junction objects are needed to link two interrelated objects together.
What Is Junction Object?
A junction object is a custom object bearing two different master-detail relationships. It is the primary object used to link two objects in a many-to-many relationship.
Junction objects are created from custom objects. Once the object is done, lookup fields for the first two primary objects to be linked are then created on the junction object.
Creating junction objects is a quick and easy way to establish many-to-many relationships on data objects that have several connections to consider.
Junction Objects in Action
Here’s an example to help you better understand how junction objects work.
Take a recruitment agency for example. An agency has several Clients looking for candidates to fill in their positions. Conversely, the agency has lots of potential Candidates looking forward to grab a client’s job offer. To link Clients and Candidates together, you may create a custom junction object common to these two objects, such as Job Vacancies.
One Client may have several candidates to consider for their vacancies. Conversely, one Candidate can apply to several clients at the same time for the same vacancies. Tracking how many clients a candidate has passed applications for, and tracking which candidates a client shortlisted may require a junction object of job vacancies.
A job vacancy can be posted by clients several times for all candidates, and they can be applied for by candidates hoping to get a job offer from one of the clients. Job Vacancies then link the Clients and Candidates objects in a many-to-many relationship in Salesforce.
In a nutshell, junction objects are used to link two primary objects together via a many-to-many relationship type. It’s basically a new custom object connecting two other objects together through lookup fields created on it.