Relationship In Salesforce

Relationship In Salesforce

1. Master-detail relationship
2. Lookup relationship
3. Self-relationship
4. External lookup relationship
5. Indirect lookup relationship
6. Many-to-many relationship (junction object)
7. Hierarchical relationship

Master-detail relationship

It is a strongly coupled relationship among Salesforce objects, which means if a master record gets deleted, then the child records associated with it are also deleted.

In this type of relationship, the parent record controls the behavior of the child record regarding visibility and sharing. It means the security setting of a parent object applies to the child object.

When there is a master-detail relationship between two objects, you can create a unique type of field over the master object, called Roll-up summary. A roll-up summary field allows us to calculate values from child records, such as the number of child records linked to a parent record.

Lookup relationship

It is a loosely coupled relationship among Salesforce objects, which means even if a parent record gets deleted, the child records remain in the system.

Here, both the parent and child have their own sharing settings and security controls. 

Self-relationship

Self-relationship is another example of a lookup relationship. In Salesforce, we can use lookup relationships to create self-relationship among objects; we can have a maximum of 40 self-lookups. For example, a campaign record can have a Parent Campaign record.

External lookup relationship

We can create two special lookups on an external object apart from the standard lookup relationship. They are external lookup relationship and indirect lookup relationship.

External lookup relationship allows us to link an external object to a parent external object whose data is stored in an external data source. In other words, it allows us to link two external objects.

Indirect lookup relationship

An indirect lookup relationship allows us to link an external object to a standard or custom object.

We can only create an indirect lookup to an object with a unique external ID field on the parent object that is used to match the records in this relationship.

While creating an indirect lookup relationship field on an external object, we have to specify the child object field and the parent object field to match and associate records in the relationship.

For example, we can display a related list of payments from the ERP external record with matching external IDs on the account object.

Many-to-many relationship (junction object)

§The many-to-many relationship in Salesforce allows us to link a child record to multiple parents.

If you have two objects, called Case and Article, and you want to relate these two objects in such a manner that one case can have multiple articles and one article is linked to many cases, then we have to use the many-to-many relationship. The many-to-many relationship is made with the help of a junction object. In this case, we can create the third object, let's say, Solution with two master-detail relationships with Solution - Case and Solution - Article.

Hierarchical relationship

In Salesforce, only a user object has this type of relationship where we can create a hierarchy of users in the organization. For example, a user can have his manager, and his manager may have senior manager, and so on till the CEO or CIO level.