They are four types of Relationships in Salesforce.com. They are

  1. Master-Detail relationship.
  2. Look-up Relationship.
  3. May-Many Relationship.
  4. Hierarchy Relationship (we can not use this relationship).

2. What is a “Look-up Relationship”?

  • No parent is required.
  • Relationship is optional.
  • No impact on Security.
  • Roll-Up summary fields cannot be available.
  • 25 look-up relationships can be created to one Object.

3. What is “Master-Detail Relationship”?

We create Master-Detail Relationship using Junction Object in Salesforce.

  • Child record must have a  associated parent.
  • Cascade record-level security.
  • Cascade record deletion.
  • Roll-up Summary fields can be established.
  • Standard objects can not be a detail object.
  • Standard Objects can be a Master object
  • Maximum 2 Master-Detail Relationships can be created to a Object.
  • Records can be re parented.

Get more details here :- Master-Detail Relationship

4. What is a “Self Relationship”?

Self Relationship is nothing but creating relationship between two same objects. This Self Relationship is a Look-up Relationship to the same object.

5. What is Roll-up summary?

Roll-Up Summary field in salesforce calculates values from a set of related records.

6. Define various characters of Roll-up Summary Field?

  1. Roll-Up Summary field can be created only in a object which is referred as a object with a master detailed relationship field.
  2. Roll-Up Summary field can only created for Master-detail Relationship.
  3. Roll-Up Summary field can not be  created for Look-up Relationship.
  4. It Derives the data from child Object.
  5. We can’t change field type of a field that we reference in a roll-up summary field.
  6. Auto numbers are not available here.
  7. Roll-Up Summary fields are not available for mapping lead fields of converted fields.

7. List out the functions of Roll-up Summary field ?

  • Count : It calculates the total number of related records.
  • Sum : It totals the values of selected fields.
  • Min : Displays lowest value.
  • Max : Displays the highest value.

8. What is Many-Many Relationship in Salesforce ?

  • Many-Many Relationships between two objects can be created.
  • Junction Object is used to create Many-Many Relationship.
  • Junction object can also be called as Join Object.
  • Junction Object links each objects in Many-Many Relationship.

9. How to create Roll-up summary field on look-up relationship?

https://www.salesforcetutorial.com/how-to-create-roll-up-summary-fields-in-salesforce/

10. Can we have Roll up Summary fields in case of Parent-Child Relationships?

No.

11. Is it possible to edit Roll up summary field value in a record?

No. roll up summary fields are read only fields and they can not be edited.

12. Is it possible to create Roll up summary field on parent object ?

Yes, we can create Roll up Summary field on parent object only with master detail relation between objects.

13. How to create Many – to – Many relationship?

https://www.salesforcetutorial.com/many-to-many-relationships-in-salesforce/

14. What is Junction Object?

In salesforce, Junction Object are the part of the objects which joins one object to another. These are specially used to join many objects in Many to Many relationships.

15. What are the main things need to consider in the “Master-Detail Relationship”?

Cascade deletion of the child records is done when parent record is deleted in Master-Detail Relationship.

16. Can we convert the look up relationship to Master Detail relationship? If so How can we convert?

Yes, we can convert Look-Up relationship to Master-Details Relationship. Conversion can be done only if all the fields have valid look-Up fields values only.’

17. Can we create Master Detail relationship on existing records?

Yes, It is possible to create Master-Detail Relationship on existing record. First we have to create Look-Up relationship to a  record then convert it to master-Detail Relationship.

18. How to create many to many relationships between two objects?

Many to Many Relationship can be created using Junction object.

Learn how to create Many to Many Relationship in Salesforce.

19. In case of Master-Detail relationship, on Update of master record can we update the field of child record using workflow rule?

No

20. In case of Master-Detail relationship, on Update of child record can we update the field of Parent record using workflow rule?

Yes, we can updatethe field of Parent record using workflow rule.

21. What happens to detail record when master record is deleted?

When master Record is deleted, it’s detail records are also deleted.

22. What happens to child record when a master record is deleted in Look-up Relationship?

Child records are not deleted.

23. A custom object contains some records, now my requirement is to create field in this object with master detail relationship.

No. we can no create master detail relationship first create look up relationship and associate look fields for every parent record and then convert this to Master detail relationship.

24. Can we create both  master detail relationship and Look-Up Relationship at a time ?

Yes, we can create.

“salesforce administrator interview questions – Relationships”