There are three main types of relationships in Salesforce: 1. Master-detail relationships model parent-child relationships where child records cannot exist without a parent record and parent deletion deletes children. Up to two master-detail relationships are allowed per object. 2. Lookup relationships can link objects without implications for security, deletion, or required fields. Up to 25 lookups are allowed. 3. Many-to-many relationships are modeled using a junction object with two master-detail relationships to the original objects. This allows each record to link to multiple others in both directions.

1. RELATIONSHIPS

2. TYPES OF RELATIONSHIP
● Master-Detail
● Look up
● Many-Many

3. Master-Detail Relationship
●
Master Detail relationship is the Parent child relationship. In which Master
represents Parent and detail represents Child. Rollup summary fields can only be
created on Master records which will calculate the SUM, AVG, MIN of the Child
records.
●
Up to 2 allowed to object.
●
Parent field on child is required.
● Access to parent determines access to children.
● Deleting parent automatically deletes child.
●
A child of one master detail relationship cannot be the parent of another.
●
Lookup field on page layout is required.
SCHOOL
CLASSROOM

4. LOOKUP RELATIONSHIP
●
Up to 25 allowed for object
●
Parent is not a required field.
● No impact on a security and access.
● No impact on deletion.
● Can be multiple layers deep.
● Lookup field is not required.
Position
Job
app 1
Job
app 2
Job
app 3

5. Many to Many Relationship
Naukri.com
Monster.com
Job Posting on
Monster.com
For Jr.Software dev
Job Posting on
Monster.com
For Sr.Software dev
Job Posting on
Naukri.com
For Sr.Software dev
Position:
Jr.Software dev
Position:
Sr.Software dev
MANY ONE MANY

6. You can use master-detail relationships 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.
To create a many-to-many relationship, simply create a custom junction object with two
master-detail relationship fields, each linking to the objects you want to relate.

7. Other Relationships
●
Junction objectsJunction objects are used to create many to many relationships between objects.
● The Recruiting application example, you can see that a Position can be linked to
many Candidates, and a Candidate can apply for different Positions. To create this
data model you need a third object "Job Application" that links the 2.
Self RelationshipSelf Relationship
An Object which uses LookUp relationship in the same object is called as Self
Relationship.