Salesforce Interview Questions

Salesforce Interview Questions

1. What is Apex Ans: It is the in-house technology of salesforce.com which is similar to Java programming with object oriented concepts and to write our own custom logic.

2. What is S-Control ?
Ans: S-Controls are the predominant salesforce.com widgets which are completely based on Javascript. These are hosted by salesforce but executed at client side. S-Controls are superseded by Visualforce now.

3. What is a Visualforce Page ?
Ans: Visualforce is the new markup language from salesforce, by using which, We can render the standard styles of salesforce. We can still use HTML here in Visualforce. Each visualforce tag always begins with “apex” namespace. All the design part can be acomplished by using Visualforce Markup Language and the business logic can be written in custom controllers associated with the Page.

4. Will Visual force still supports the merge fields usage like S-control ?
Ans: Yes. Just like S-Controls, Visualforce Pages support embedded merge fields, like the {!$User.FirstName} used in the example.

5. Where to write Visualforce code ?
Ans: You can write the code basically in 3 ways.

1. setup->App Setup->Develop->Pages and create new Visulaforce page.
2. Setup -> My Personal Information -> Personal Information -> Edit check the checkbox development mode. When you run the page like this, https://ap1.salesforce.com/apex/MyTestPage. you will find the Page editor at the bottom of the page. You can write you page as well as the controller class associated with it, there it self.
3. Using EclipseIDE you can create the Visulaforce page and write the code.

6.What are Apex Governor Limits?

Governor limits are runtime limits enforced by the Apex runtime engine. Because Apex runs in a shared, multitenant environment, the Apex runtime engine strictly enforces a number of limits to ensure that code does not monopolize shared resources. Types of limits that Apex enforces are resources like memory, database resources, number of script statements to avoid infinite loops, and number of records being processed. If code exceeds a limit, the associated governor issues a runtime exception.

Explains the basic difference in Sandbox and developer edition of Salesforce

A test environment for salesforce.com is crucial to change control. Salesforce.com provides the tools needed to test anything in a test environment before you implement it in your live instance. You can either test in a Sandbox environment or in a Developer environment. What is the difference? I will share what I know…

Sandbox

The salesforce.com Sandbox environment is an exact copy of your salesforce.com instance. You can copy your live instance to a sandbox environment (but you have to perform manually from sandbox to developer edition) where you can test any changes, implementations, AppExchange apps or updates. It can also be your hands-on training environment without risking your live data.

You can either copy your configuration and data into a sandbox environment or just the configuration. It acts exactly like your live instance, but be careful if you have workflow rules or automations because they will work in the sandbox as well.

I know that this sounds wonderful and if you don’t have it, you are dying to know how to get it. The problem is the cost. If you are on Unlimited Edition, then cost is not a problem because it comes included. But for Enterprise, Professional or Group Editions, you have to pay… and the price is hefty; anywhere between 25k-50k per year. For a lot of companies, that is more than they are paying for their live salesforce.com instance. So how do you test salesforce.com without Sandbox?  It is always suggested to develop application in sandbox instance then go for LIVE.

Developer Edition

Developer Edition was an edition created for development of integrations and apps, specifically for the AppExchange. It is also a great tool for testing/training in salesforce.com. What makes this a great tool is the fact that it is free. Anyone can get a Developer Edition of salesforce.com. It is a standard Enterprise Edition with very limited storage space. You cannot copy your configuration or data onto the Developer Edition, but you can customize it to match your instance’s look and feel. Once it is customized, you can use it for training, testing or anything else you want. It takes a little bit of work, but you can make it act and feel just like your live instance. The work is well worth it for the free price.

10. Do governor limits apply to sandbox instances?

Ans : Governor limits do apply to all Salesforce instances (trial, developer, production or sandbox environments). However code coverage and successful execution of test classes is only enforced when deploying to a production environment.

11. What is difference in ISNULL and ISBLANK?

ISNULL:

• Determines if an expression is null (blank) and returns TRUE if it is. If it contains a value, this function returns FALSE.
• Text fields are never null, so using this function with a text field always returns false. For example, the formula field IF(ISNULL(new__c) 1, 0) is always zero regardless of the value in the New field. For text fields, use the ISBLANK function instead.
• Multi-select picklist fields are never null in s-controls, buttons, and email templates, so using this function with a multi-select picklist field in those contexts always returns false.
• Empty date and date/time fields always return true when referenced in ISNULL functions.
• Choose Treat blank fields as blanks for your formula when referencing a number, percent, or currency field in an ISNULL function. Choosing Treat blank fields as zeroes gives blank fields the value of zero so none of them will be null.
• Merge fields can be handled as blanks, which can affect the results of components like s-controls because they can call this function.
• When using a validation rule to ensure that a number field contains a specific value, use the ISNULL function to include fields that do not contain any value. For example, to validate that a custom field contains a value of ‘1,’ use the following validation rule to display an error if the field is blank or any other number: OR(ISNULL(field__c), field__c<>1)

ISBLANK:

• Determines if an expression has a value and returns TRUE if it does not. If it contains a value, this function returns FALSE.
• Use ISBLANK instead of ISNULL in new formulas. ISBLANK has the same functionality as ISNULL, but also supports text fields. Salesforce.com will continue to support ISNULL, so you do not need to change any existing formulas.
• A field is not empty if it contains a character, blank space, or zero. For example, a field that contains a space inserted with the spacebar is not empty.
• Use the BLANKVALUE function to return a specified string if the field does not have a value; use the ISBLANK function if you only want to check if the field has a value.
• If you use this function with a numeric field, the function only returns TRUE if the field has no value and is not configured to treat blank fields as zeroes.

for further study you can read this link.

12. Is it possible to write the Apex code from user Interface?

You can add, edit, or delete Apex using the Salesforce.com user interface only in a Developer Edition organization, a Salesforce.com Enterprise Edition trial organization, or sandboxorganization. In a Salesforce.com production organization, you can only make changes to Apex by using the Metadata API ,

deploycall, the Force.com IDE, or theForce.com Migration Tool. The Force.com IDE and Force.com Migration Tool are free resources provided by salesforce.com to support its users and partners, but are not considered part of our Services for purposes of the salesforce.com Master Subscription Agreement.

13. When you can’t add Time dependent action in Workflow rule?
You can’t add time-dependent actions to a rule if you choose Every time a record is created or edited.

14. What are the types of email templates available in salesforce.com?

1. Text
2. HTML with Letter Head
3. Custom HTML
4. Visual force

15. What are the different Salesforce.com Editions and Limits?

Ans : 

16. What is Roll up summary field in Salesforce?

Roll up summary field in salesforce calculates the Count, Sum, Min or Max of particular field of any child record. Thus, we can say that Roll up summary field can only be created on Master object.

17. What will happen if the Account is deleted?

If the Account is deleted then Contact, Opportunity will also be deleted from Salesforce which are related to that Account.

From the database perspective, check below image of child relationships of Account:

Account Child relationship in salesforce

If we use schema builder, released in Winter 12 it would look like:

Account Contact and Opportunity of salesforce in schema builder

18. How many types of the relationship fields available in Salesforce?

Ans :

1. Master Detail
2. Many to Many
3. Lookup
4. Hierarchical (It is available only on User Object, we cannot create this relationship)

19. How to create many to many relationships between object?

Creating many to many relationship in salesforce is little tricky. You cannot create this type of relationship directly. Follow below steps to create this type of relationship.

Create both objects which should be interlinked.

Create one custom object (also called as junction object), which should have autonumber as unique identification and create two master relationships for both objects, no need create tab for this object.

Now on both object, add this field as related list.

20. In Which sequence Trigger and automation rules run in Salesforce.com

Ans : The following is the order Salesforce logic is applied to a record.

1. Old record loaded from database (or initialized for new inserts)
2. New record values overwrite old values
3. System Validation Rules
4. All Apex “before” triggers
5. Custom Validation Rules
6. Record saved to database (but not committed)
7. Record reloaded from database
8. All Apex “after” triggers
9. Assignment rules
10. Auto-response rules
11. Workflow rules
12. Escalation rules
13. Parent Rollup Summary Formula value updated (if present)
14. Database commit
15. Post-commit logic (sending email)

Additional notes: There is no way to control the order of execution within each group above.

21. If one object in Salesforce have 2 triggers which runs “before insert”. Is there any way to control the sequence of execution of these triggers?

Ans : Salesforce.com has documented that trigger sequence cannot be predefined. As a best practice create one trigger per object and use comment blocks to separate different logic blocks. By having all logic in one trigger you may also be able to optimize on your SOQL queries.

22. How to delete the User from Salesforce?

Ans : As per now, salesforce does not allow to delete any user, however you can deactivate the user.

23. How to delete the users data from Salesforce?

Ans : To delete the Users Data go to Setup | Administration Setup | Data Management |  Mass Delete Record, from there select the objects like Account, Lead etc and in criteria select the users name and delete all records of that user related to particular object.

24. How to restrict the user to see any record, lets say opportunity?

Ans : set up opportunity sharing to be private.  If both users are admins or have view all records on opportunity, then that overrides private sharing.

25. What is the difference between trigger.new and trigger.old in Apex – SFDC?

Ans :

Trigger.new :

Returns a list of the new versions of the sObject records.

Note that this sObject list is only available in insert and update triggers, and the records can only be modified in before triggers.

Trigger.old :

Returns a list of the old versions of the sObject records.

Note that this sObject list is only available in update and delete triggers.

26. How to restrict any Trigger to fire only once OR how we can avoid repeated or multiple execution of Trigger?

Ans:

Triggers can fire twice, once before workflows and once after workflows, this is documented at

http://www.salesforce.com/us/developer/docs/apexcode/ Content/ apex_triggers_order_of_execution.htm:

“The before and after triggers fire one more time only if something needs to be updated. If the fields have already been set to a value, the triggers are not fired again.”

Workaround:

Add a static boolean variable to a class, and check its value within the affected triggers.

    public class HelperClass {
	public static boolean firstRun = true;
	}
	
	trigger affectedTrigger on Account (before delete, after delete, after undelete) {
		 if(Trigger.isBefore){
			if(Trigger.isDelete){
				 if(HelperClass.firstRun){
					Trigger.old[0].addError('Before Account Delete Error');
					HelperClass.firstRun=false;
				 }
			}
		 }
	
	}

27.  What is difference between WhoId and WhatId in the Data Model of Task ?

Ans :

WhoID refers to people things. So that would be typically a Lead ID or a Contact ID
WhatID refers to object type things. That would typically be an Account ID or an Opportunity ID

28. Where is the option of the report for the “Custom Object with related object” and what are the condition to generate related reports?
Ans :

If the parent object is the standard object provided by the salesforce like “Account”, “Contact” then the report will be in there section with related custom object.
If both objects are the custom then the report will be in “Other Reports” Sections.

Following are the conditions to get the report of related objects:

• On both the objects, Reports option must be enable.
• Both object must be related either using Lookup or Master Detail type of field.

29. How you can provide the User Login (Authentication) in Public sites created by Salesforce.

Answer : We can provide the authentication on public sites using “Customer Portal”.

30 : What is the dynamic Apex?
Ans :
Dynamic Apex enables developers to create more flexible applications by providing them with the ability to “Access sObject and field describe information”, “Write Dynamic SOQL Queries”, “Write Dynamic SOSL Queries” and “Dynamic DML”.

31 : How to get the list of all available sobject in salesforce database using Apex (Dynamic Apex)?
Ans:

33 : How to get all the fields of sObject using dynamic Apex?
Ans:

	Map<String, Schema.SObjectType> m  = Schema.getGlobalDescribe() ;
	Schema.SObjectType s = m.get('API_Name_Of_SObject') ;
	Schema.DescribeSObjectResult r = s.getDescribe() ;
	Map<String,Schema.SObjectField> fields = r.fields.getMap() ;

34 : How to get all the required fields of sObject dynamically?
Ans:
There is no direct property available in Apex dynamic API to represent the required field. However there is another way to know about it.
If any field have below three properties then it is mandatory field.

1. If it is Creatable
2. If it is not nillable and
3. If it does not have any default value

Map<String, Schema.SObjectType> m  = Schema.getGlobalDescribe() ;
Schema.SObjectType s = m.get(so.apiName) ;
Schema.DescribeSObjectResult r = s.getDescribe() ;
Map<String,Schema.SObjectField> fields = r.fields.getMap() ;
for(String f : fields.keyset()){
Schema.DescribeFieldResult desribeResult = fields.get(f).getDescribe();
if( desribeResult.isCreateable()  && !desribeResult.isNillable() && !desribeResult.isDefaultedOnCreate());
}
}

35 : How to display error messages in the visualforce page ?
Ans:
In Apex use below code to create the error message for visualforce.

in Visualforce page add below tag where you want to display the error message.

<apex:pageMessages ></apex:pageMessages>

36 : What is property in Apex? Explain with advantages.
Ans: 
Apex mainly consist of the syntax from the well known programming language Java. As a practice of encapsulation in java we declare any variable as private and then creates the setters and getters for that variable.

However, the Apex introduced the new concept of property from language C# as shown below:

37 : What is the controller extension ?
Ans:
Any apex class having a public constructor with Custom Controller or Standard Controller object as a single argument is known as controller extension.

38 : Explain the need or importance of the controller extension.
Ans:
Controller extension is very useful and important concept introduced by the salesforce recently. It gives the power to programmer to extend the functionality of existing custom controller or standard controller.
A Visualforce can have a single Custom controller or standard controller but many controller extensions.
we can say that the custom extension is the supporter of custom or standard controller.
Consider one example : If there is one controller written and used by the multiple visualforce pages and one of them needs some extra logic. Then instead of writing that logic to controller class (Which is used by many visualforce pages) we can create a controller extension and apply to that page only.

39 : How to read the parameter value from the URL in Apex?
Ans:
Consider that the parameter name is “RecordType”.

1String recordType = Apexpages.currentPage().getParameters().get(‘RecordType’);

40. What is Master Detail relationship and look up relationship in Salesforce?
Ans:
Master Detail relationship is the Parent child relationship. In which Master represents Parent and detail represents Child. If Parent is deleted then Child also gets deleted. Rollup summary fields can only be created on Master records which will calculate the SUM, AVG, MIN of the Child records.
Look up relationship is something like “has-a” (Containership) relationship. Where one record has reference to other records. When one record is deleted then there is no impact on other records.

41. Can we convert the lookup relationship to Master Detail relationship?
Ans:
We can convert the lookup relationship to master detail relationship if and only if all the existing record has valid lookup field.

42. In How many way we can invoke the Apex class?
Ans:

1. Visualforce page
2. Trigger
3. Web Services
4. Email Services

43. Can we create Master Detail relationship on existing records?
Ans:
No. As discussed above, first we have to create the lookup relationship then populate the value on all existing record and then convert it.

44. How validation rules executed? is it page layout / Visualforce dependent?
Ans :
The validation rules run at the data model level, so they are not affected by the UI. Any record that is saved in Salesforce will run through the validation rules.

45. What is the difference between database.insert and insert ?
Ans:
insert is the DML statement which is same as databse.insert. However, database.insert gives more flexibility like rollback, default assignment rules etc. we can achieve the database.insert behavior in insert by using the method setOptions(Database.DMLOptions)
Important Difference:

• If we use the DML statement (insert), then in bulk operation if error occurs, the execution will stop and Apex code throws an error which can be handled in try catch block.
• If DML database methods (Database.insert) used, then if error occurs the remaining records will be inserted / updated means partial DML operation will be done.

46. What is the scope of static variable ?
Ans:
When you declare a method or variable as static, it’s initialized only once when a class is loaded. Static variables aren’t transmitted as part of the view state for a Visualforce page.

Static variables are only static within the scope of the request. They are not static across the server, or across the entire organization.

47. Other than SOQL and SOSL what is other way to get custom settings?
Ans:
Other than SOQL or SOSL, Custom seting have there own set of methods to access the record.
For example : if there is custom setting of name ISO_Country,

SO_Country__c code = ISO_Country__c.getInstance('INDIA');
Map<String,ISO_Country__c> mapCodes = ISO_Country__c.getAll();
System.debug('ISO Code: '+mapCodes.get('INDIA').ISO_Code__c);
//Alternatively you can return the map as a list:
List<String> listCodes = ISO_Country__c.getAll().values();

48. What happen if child have two master records and one is deleted?
Ans :
Child record will be deleted.

49. What is Difference in render, rerender and renderas attributes of visualforce?
Ans:
render – It works like “display” property of CSS. Used to show or hide element.
rerender – After Ajax which component should be refreshed – available on commandlink, commandbutton, actionsupport etc.
renderas – render page as pdf, doc and excel.

50. What is Scheduler class in Apex and explain how to use Crone statement to Schedule Apex class?
Ans:
The Apex class which is programed to run at pre defined interval.
Class must implement schedulable interface and it contains method named execute().
There are two ways to invoke schedular :

1. Using UI
2. Using System.schedule

The class which implements interface schedulable get the button texted with “Schedule”, when user clicks on that button, new interface opens to schedule the classes which implements that interface.
To see what happened to scheduled job, go to “Monitoring | Scheduled jobs ”

Example of scheduling :

scheduledMerge m = new scheduledMerge();
String sch = '20 30 8 10 2 ?';
system.schedule('Merge Job', sch, m);

To see how to make crone job string – Refer this Online Crone Expression Generator tool .

Note : Salesforce only accepts integer in Seconds and Minutes. So, lets say if you want to run Apex job on every 10 minutes, crone statement will be ‘0 0/10 * 1/1 * ? *’ and salesforce will throw an error saying “System.StringException: Seconds and minutes must be specified as integers“. That mean like Time based Workflow, minimum interval to schedule job is 1 hour.