Frequently asked Salesforce Interview questions with answers - Part 2

1) Can we Undelete the records after 20 days of deletion?
No. We can only Undelete the records within 15 days of deletion. Beyond 15 days, we need to contact Salesforce to get the records.

2) Explain different types of relationship in Salesforce.

There are three important relationships available in Salesforce.

Lookup Relationship:

1. It is a Parent - Child relationship where Parent is not a required field in Child object.
2. We can have upto 25 lookup relationships in single object.
3. Child record will not be deleted if Parent record is deleted.
4. No impact on Security and Access.

Master-Detail Relationship:

1. It is a Parent - Child relationship where Parent is required field in Child object.
2. We can have upto 2 Master-Detail relationships in single object.
3. Rollup Summary field can only be created on Master in Master-Detail relationship.
4. Child record will be deleted, if Parent record is deleted.
5. Access to Master record gives access to Detail records.

Many-to-Many Relationship : 

1. Many-to-Many relationship allows each record of one object to link with multiple records of other object and vice versa.
2. This can be achieved by using Junction object.
3. Junction object is a Custom object with two Master-Detail Relationship.

3) What is a relationship between Accounts and Contacts?

They show lookup relationship because Account field is not required on Contact page but they also show Master-Detail relationship because contact gets deleted when Account is deleted.

However, they have lookup relationship and it has a property called CascadeDelete set to True and this is why Contacts gets deleted when Account is deleted

4) What is workflow?

Workflows help in automating four actions based on the Evaluation criteria set by user.

Evaluation Criteria:

1. When Record is Created.
2. When Record is Created and Edited.
3. When record is Created and Edited to meet rule criteria.

Actions:

1. Create new Task.
2. Send Email alert.
3. Field Update.
4. Outbound Message.

5) How to populate account field in contacts without coding?

This can be achieved by using cross object formula field in Contacts.

6) How to get count of Child records in Parent object having lookup relationship.

This can be done using Trigger.

Check Sample Trigger at : http://anupkabra.blogspot.in/2017/08/trigger-to-update-total-number-of.html

7) What is Custom setting and explain its types?

Custom Setting is similar to Custom Objects which lets you customize org data. It saves data in Cache memory, which makes is effective as there wont be any limitation of retrieving data unlike custom object. There are two types of Custom Settings:

List Custom Setting: This custom setting provides data which will remain same for entire organization. Every user will view same set of data.

Hierachy Custom Setting: This custom setting provides data which will differ based on the users access. It will show/restrict data based on users permission.

8) What is Joined Reports?

Joined reports helps in generating a report using multiple report types. Report types are added as blocks and we can add upto 5 record types in a single Joined reports.

9) What is Field Bucket?

Field Bucket helps in categorizing records in reports without adding any formula or extra custom field. 

10) What is Dynamic Dashboard?

Dynamic dashboard are used to display information tailored to a specific user, while normal dashboard shows data only from single users perspective. Dynamic dashboards should be used when each user has to see "User-Specific data".

11) What are components of dashboard?

1. Chart
2. Gauge
3. Metric
4. Table
5. Visualforce Pages

12) What are Custom Metadata types.

Custom Metadata types are similar to custom setting with many advance features. One of the best feature of custom metadata is that both "Data" and "Metadata" deployed together unlike custom setting where only Metadata is deployed first and then data has to be moved manually.

13) What is __r?
__r represents a custom relationship between two objects. we use it when we query a custom relationship from Parent to child or vice versa.

For example:

Child__c is a child object and Parent__c is a Parent object.

Child to Parent relationship query:
Select ID, Parent__c, Parent__r.Name from Child__c;
Parent to Child relationship query:
Select ID, Name, (Select ID, Name from Child__c) from Parent__c;

14) What will happen if we Undelete the deleted Junction object?
If we Undelete the deleted Junction object, Master-Detail relationship will convert to Lookup Relationship.

15) What is Batch Apex? How to know status of the Batch Job?
Batch Apex is an asynchronous process which is used to process millions of records. It uses three methods, Start, Execute and Finish.

Status can be found using below query:

AsyncApexJob a = [Select ID, Status, NumberOfErrors, TotalJobItems, CreatedBy.Email from AsyncApexJob where ID =:BC.getJobID()];

16) What is Wrapper Class?
Wrapper Class is a container Class whose instances are the collection of other objects. It is a custom object defined by developer where he defines the property of the class.

17) What will happen if we perform "Update" on "After Update" trigger?
It will result in recursive trigger.

18) What is constructor?
A constructor is a special method that is used to initialize a newly created object and is called just after memory is allocated for the object.

19) Approach to view all records related to user from account whenever visualpage loads
We will use custom controller with constructor having a query to display data based on user.

20) Explain different types of controller?
There are three types of controller.

Standard Controller: They are the default controllers provided by Force.com. These standard controllers will have same logic and functionality which are used in visaulforce pages. Coding is not required.
<apex:page standardcontroller = "contact">

Custom Controller: These are used when developer need a functionality which cannot be fulfilled by Standard controller. These require coding.
<apex:page controller = "testApexCode">

Extension controller: In order to use both standard and custom controllers functionality, we use extension controller.
<apex:page standardcontroller = "contact" extensions = "testApexCode">

21) How to make Apex REST call using custom button?
Using below command in custom button:
sforce.apex.execute("classname", "methodname",{parameter passed to method}

22) How to load attachments using Dataloader?
Create an attachments.csv file (the name of the file is unimportant) with the following column headers:

ParentId - ID of the record to which the attachment should be associated 
Name - Name of the attachment 
ContentType - Format of the extension (e.g. .xls, .pdf, etc) 
OwnerID - ID for the owner of the attachment
Body - File path to the Attachment on the local machine (C:\documents and 
settings\schun\desktop\attachments\file.xls)

Log in to the Data Loader. Select the "Insert" command. In the 'Select Sforce Object' step, select the 'Show all Sforce Objects' checkbox and then select "Attachments". Choose the attachments.csv file. In the mapping step, map the following fields:

Parent ID 
Name 
Owner ID 
Body - Make sure to map the Body column which you created previously with the file extension. 

This is how you designate the file and location of the attachments to be inserted. 
Click "OK" to proceed with the insert. It may take a few minutes but the attachments should be successfully uploaded to your salesforce org.

23) What is Mixed DML error?
DML operations on certain sObjects, sometimes referred to as setup objects, can’t be mixed with DML on other sObjects in the same transaction. This restriction exists because some sObjects affect the user’s access to records in the org. You must insert or update these types of sObjects in a different transaction to prevent operations from happening with incorrect access-level permissions. For example, you can’t update an account and a user role in a single transaction. However, deleting a DML operation has no restrictions.

24) How to avoid Mixed DML error in Test methods?
Use @future to Bypass the Mixed DML Error in a Test Method.

Part 1 : Salesforce Interview Questions

Part 3 : Salesforce Interview Questions

Cheers !
Facebook - anupkabravlogs
Instagram - anupkabravlogs
YouTube   - Anup Kabra Vlogs