Ans:
Cloud Computing is an approach to provide the following services -- SAAS (Software As A Service)
- PAAS (Platform As A Service)
- IAAS (Infrastructure As A Service)
Ans:
- Salesforce is a company which provides a web based tool called Salesforce
- Salesforce by following the Cloud Computing approach, providing SAAS and PAAS
- SAAS: Providing Sales, Marketing and Call Center applications as a service
- PAAS: Providing Force.com platform in which we can develop Apex (Programming language similar to Core Java) and Visualforce (Mark up language similar to HTML) logic.
Ans:
MVC (Model View Controller ) Architecture Contains three components Model,View and Controller.
Model is the Database ,
View is the user interface ,
Controller is the Business Logic.
Model View Controller architecture separates the user interface layer which is called VIEW from the data layer called MODEL.
Model is the Database ,
View is the user interface ,
Controller is the Business Logic.
Model View Controller architecture separates the user interface layer which is called VIEW from the data layer called MODEL.
Controller layer is between Model layer and View layer. This layer connects both View and Model.
Salesforce follows MVC architecture,
In Salesforce point of view
View component defines how the data is represented. Visualforce pages, Standard pages are the view components. Page layouts,Apps and Tabs are also comes under this components.
Controller components defines the business logic. Here we have standard controller and custom controllers. Some of the components under this category are Apex classes, triggers, workflows, approvals and validation rules,(Save, Edit, New, Cancel and Delete - upon click on these button salesforce execute some logic from controller).
Ans:
- In Salesforce, whenever user create any component (Object, field, tab etc...) or record then salesforce will generate an unique id with which user can identify the record or component.
- After creating the record, in the URL user can see the id of the record which is of 15 digits length.
- Through user interface user always see 15 digit id which is Cases-Sensitive.
- If the user query the existing records from the database through API (Either from Query Tool or from a program), it will always return 18 digit id which is Case-Insensitive.
- Last 3 digits of the 18 digit represents checksum of the capitalization of 15 digit id.
- Based on the first 3 digits user can identify the object of the record.
- All the records belongs to same object will contain same first 3 digits.
9.Object Relationships?
Ans:
- Master-detail
- Many-to-many
- Lookup
- External lookup : An external lookup relationship links a child standard, custom, or external object to a parent external object
- Indirect lookup : An indirect lookup relationship links a child external object to a parent standard or custom object.
- Hierarchical : A special lookup relationship available for only the user object. It lets users use a lookup field to associate one user with another that does not directly or indirectly refer to itself.
10. Difference between standard controller and custom controller ?
Ans:
Standard controller:
If VF uses Standard controllers then it contains the functionality and logic that are used for standard Salesforce pages. For example, if you use the standard Accounts controller, clicking a Save button in a Visualforce page results in the same behavior as clicking Save on a standard Account edit page.
A standard controller exists for every Salesforce object that can be queried using the Force.com API.
Custom controller:
A custom controller is an Apex class that implements all of the logic for a page without leveraging a standard controller. Use custom controllers when you want your Visualforce page to run entirely in system mode, which does not enforce the permissions and field-level security of the current user.
- Override existing functionality
- Make new actions available to the page
- Customize the navigation
- Use HTTP callouts or web services
- Have greater control of how information is accessed on the page
A controller extension is an Apex class that extends the functionality of a standard or custom controller. Use controller extensions when:
REST : Representational State Transfer
* REST and SOAP are the two web service frameworks available on the Force.com platform.
* The SOAP API uses authentication with username and password, and communicates using XML messages. There are different API's to work with the Enterprise, Partner, Bulk, Metadata etc.
*The REST API uses HTTP to authenticate, it uses a token authentication and can use OATH to authenticate, it communicates using JSON messages.
*REST API is generally lighter weight than the SOAP API, works well with mobile applications especially.
JSON is mostly preferred as it is light weight and therefore REST API's are most suited for mobile and web applications.
* SOAP works with WSDL and REST works with GET, POST, PUT, DELETE
* SOAP Handles large data load and fit for large enterprise applications and REST Handles less data and fit for mobile and web applications.
- You want to leverage the built-in functionality of a standard controller but override one or more actions, such as edit, view, save, or delete.
- You want to add new actions.
11. What is the difference between workflow and process builder ?
Ans:
You can use the Process Builder to perform more actions than with workflow:
- Create a record
- Update any related record
- Use a quick action to create a record, update a record, or log a call
- Launch a flow
- Send an email
- Post to Chatter
- Submit for approval
- Call apex methods
But the process builder doesn’t support outbound messages.
Workflow does only 4 actions
- Create Task
- Update Field
- Email Alert
- Outbound Message
12. What is the outbound message ?
Ans:
Outbound messaging is part of the workflow rule functionality in Salesforce. Workflow rules watch for specific kinds of field changes and trigger automatic Salesforce actions, such as sending email alerts, creating task records, or sending an outbound message to external services. Outbound messages can contain database field values.
Outbound messaging uses the notifications() call to send SOAP messages over HTTP(S) to a designated endpoint when triggered by a workflow rule.
After you set up outbound messaging, when a triggering event occurs, a message is sent to the specified endpoint URL. The message contains the fields specified when you created the outbound message. Once the endpoint URL receives the message, it can take the information from the message and process it.
13. Difference between SOAP and REST API ?
Ans:
SOAP : Simple Object Access ProtocolREST : Representational State Transfer
* REST and SOAP are the two web service frameworks available on the Force.com platform.
* The SOAP API uses authentication with username and password, and communicates using XML messages. There are different API's to work with the Enterprise, Partner, Bulk, Metadata etc.
*The REST API uses HTTP to authenticate, it uses a token authentication and can use OATH to authenticate, it communicates using JSON messages.
*REST API is generally lighter weight than the SOAP API, works well with mobile applications especially.
JSON is mostly preferred as it is light weight and therefore REST API's are most suited for mobile and web applications.
* SOAP works with WSDL and REST works with GET, POST, PUT, DELETE
14.How can you expose REST API ?
Ans:
At Class level
@RestResource(urlMapping='/yourUrl')
At Method Level
15. Order of Execution?
Ans:
1. Old record loaded from database (or initialized for new inserts)
2. New record values overwrite old values
3. System Validation Rules (If inserting Opportunity Products, Custom Validation Rules will also fire in addition to System Validation Rules)
4. All Apex before triggers (EE / UE only)
5. Custom Validation Rules
6. Record saved to database (but not committed)
7. Record reloaded from database
8. All Apex after triggers (EE / UE only)
9. Assignment rules
10. Auto-response rules
11. Workflow rules
12. Processes
13. Escalation rules
14. Parent Rollup Summary Formula value updated (if present)
15. Database commit
16. Post-commit logic (sending email)
2. New record values overwrite old values
3. System Validation Rules (If inserting Opportunity Products, Custom Validation Rules will also fire in addition to System Validation Rules)
4. All Apex before triggers (EE / UE only)
5. Custom Validation Rules
6. Record saved to database (but not committed)
7. Record reloaded from database
8. All Apex after triggers (EE / UE only)
9. Assignment rules
10. Auto-response rules
11. Workflow rules
12. Processes
13. Escalation rules
14. Parent Rollup Summary Formula value updated (if present)
15. Database commit
16. Post-commit logic (sending email)
16. Difference between database.query and database.QueryLocator ?
Ans:
database.query allows you to make a dynamic SOQL query at runtime. You can build up a string and then use that as a query string at run time in the database.query.it supports 50,000 records only.
database.getQueryLocator returns a Query Locator that runs your selected SOQL query returning list that can be iterated over in batch apex.
it supports upto 50 million records.
If VF page have read only attribute, use Database.getQueryLocator().
17. What is Synchronous and Asynchronous ?
Ans:
Synchronous:In a Synchronous call, the thread will wait until it completes its tasks before proceeding to next. In a Synchronous call, the code runs in single thread.
Example:
Trigger
Controller Extension
Custom Controller
Asynchronous:
In a Asynchronous call, the thread will not wait until it completes its tasks before proceeding to next. Instead it proceeds to next leaving it run in separate thread. In a Asynchronous call, the code runs in multiple threads which helps to do many tasks as background jobs.
Example:
Batch
@future Annotation
18. What is the difference between trigger.new and trigger.old?.When do use ?
Ans:
Trigger.new Returns a list of new version of sObject records.Trigger.Old Returns a list of old version of sObject records.
trigger.new used in Insert and Update.
trigger.old used in Update and Delete.
No trigger.new in Delete.
No trigger.old in Insert.
– We cannot delete trigger.new
– In before triggers, trigger.new can be used to update the fields on the same object.
– In After trigger, we get run time exception is thrown when user try to modify the fields in the same object.
19. How to restrict the trigger to Recursion?
Ans:
Trigger:
trigger updateTrigger on anyObject(after update) {
if(checkRecursive.runOnce()) {
//write your code here
}
}
Class:
public Class checkRecursive{
private static boolean run = true;
public static boolean runOnce(){
if(run){
run=false;
return true;
}else{
return run;
}
}
}
20. How many methods are available in batch apex?
Ans:
The Database.Batchable interface contains three methods that must be implemented.Start method:
global (Database.QueryLocator | Iterable<sObject>) start(Database.BatchableContext ***bc***) {}
global void execute(Database.BatchableContext ***BC***, list<P>){}
global void finish(Database.BatchableContext ***BC***){}
21. Salesforce Governor limits.
Ans:
Total number of SOQL queries - 100
Total number of DMLs - 150
Total number of records retrieved by SOQL - 50000
Total number of callouts - 100
Maximum number of batch Apex jobs in the Apex flex queue - 100
Maximum number of batch Apex jobs queued or active - 5
22. What is call-out and when we can use them?
Ans:
Apex Callouts enable Apex to invoke external web services.
Each callout request is associated with an HTTP method and an endpoint. The HTTP method indicates what type of action is desired.
GET Retrieve data identified by a URL.
POST Create a resource or post data to the server.
DELETE Delete a resource identified by a URL.
PUT Create or replace the resource sent in the request body.
Maximum number of batch Apex jobs in the Apex flex queue - 100
Maximum number of batch Apex jobs queued or active - 5
22. What is call-out and when we can use them?
Ans:
Apex Callouts enable Apex to invoke external web services.
Each callout request is associated with an HTTP method and an endpoint. The HTTP method indicates what type of action is desired.
GET Retrieve data identified by a URL.
POST Create a resource or post data to the server.
DELETE Delete a resource identified by a URL.
PUT Create or replace the resource sent in the request body.
GET the data from server
Http http = new Http();
HttpRequest request = new HttpRequest();
request.setEndpoint('https://th-apex-http-callout.herokuapp.com/animals');
request.setMethod('GET');
HttpResponse response = http.send(request);
// If the request is successful, parse the JSON response.
if (response.getStatusCode() == 200) {
// Deserialize the JSON string into collections of primitive data types.
Map<String, Object> results = (Map<String, Object>) JSON.deserializeUntyped(response.getBody());
// Cast the values in the 'animals' key as a list
List<Object> animals = (List<Object>) results.get('animals');
System.debug('Received the following animals:');
for (Object animal: animals) {
System.debug(animal);
}
}
23. What is FUTURE method ?
Ans:
A future method runs in the background, asynchronously. You can call a future method for executing long-running operations, such as callouts to external Web services or any operation you’d like to run in its own thread, on its own time. You can also make use of future methods to isolate DML operations on different sObject types to prevent the mixed DML error.
24. Difference between Public and Global in Salesforce?
Ans:
public
This means the method or variable can be used by any Apex in this application or namespace.
global
This means the method or variable can be used by any Apex code that has access to the class, not just the Apex code in the same application. This access modifier should be used for any method that needs to be referenced outside of the application, either in the SOAP API or by other Apex code. If you declare a method or variable as global, you must also declare the class that contains it as global.
25. Have you used Offset in SOQL?
Ans:
The SOQL query normally returned 100 rows, you could use OFFSET 20 in your query to skip the first 20 rows and returns 21th row to 120th rows.SELECT Name FROM Account WHERE Industry = 'Media' ORDER BY Name LIMIT 100 OFFSET 20
OFFSET keyword can be used to implement pagination in visaulforce page tables.
26. Wrapper Class ?
Ans:
A wrapper or container class is a class, a data structure, or an abstract data type which contains different objects or collection of objects as its members
In the Visualforce most important use case is to display a table of records with a check box and then process only the records that are selected.
27. What is External ID ?
Ans:
External ID
You can have multiple records with the same external ID.
This is a setting for the field that will prevent you from using the same value in multiple records for the unique field.
28. Exceptions in Apex ?
Ans:
SObjectExceptionCalloutException
DmlException
EmailException
LimitException
JSONException
ListException
NullPointerException
QueryException
StringException
TypeException
VisualforceException
RequiredFeatureMissing
NoSuchElementException
MathException
InvalidParameterValueException
29. SOQL query to get the deleted Rows also ?
Ans:
List<account> accs = [SELECT ID FROM account ALL ROWS];
System.debug(accs.size());
30. Delegate Administrative ?
Ans:
Use delegated administration to assign limited admin privileges to users in your org who aren’t administrators.
ICANN project Short
Description:
ICANN (Internet Corporation for Assigned Names and Numbers)
is US based a non-profit organization responsible for providing Domain name to
the Requested Users.
Previously ICANN is using a Drupal system for managing
the Requests raised for domain, We migrated that entire system to the
Salesforce.Now when an end user requested for a domain from drupal system a
Request will be created in Salesforce Org under Request object.Every Request is
Related to a Domain(TLD Object in salesforce),Every TLD object is related to a Registry(Account
object in salesforce),everyregistry will have Contact(Registry manager).there
is a junction object which will relate many Registries to many registry
managers.
Once an end user request for a domain an email will be
sent to the Registry manager with request details including request Url in
Community and end user details using Trigger.Registry manager can click on the
link in the mail it will take them to Community there they will be able to see
the all the requests and they can Accept those Requests or Decline those
requests.
// prime numbers printing code
for(integer i=1;i<=90;i++)
{
integer count =0;
for(integer j=1;j<=i;j++){
if(math.mod(i,j)==0)
count++;
}
// system.debug(count);
if(count==2){
system.debug(i);
}
}
// num is prime or not checking
integer count =0;
for(integer j=1;j<=2;j++){
if(math.mod(2,j)==0)
count++;
}
if(count==2){
system.debug('yes prime number');
}
else{
system.debug('no not a prime number');
}
// displaying numbers from 100 to 1
for(integer i=0;i<100;i++)
{
integer j=100-i;
system.debug(j);
}
// prime numbers printing code
for(integer i=1;i<=90;i++)
{
integer count =0;
for(integer j=1;j<=i;j++){
if(math.mod(i,j)==0)
count++;
}
// system.debug(count);
if(count==2){
system.debug(i);
}
}
// num is prime or not checking
integer count =0;
for(integer j=1;j<=2;j++){
if(math.mod(2,j)==0)
count++;
}
if(count==2){
system.debug('yes prime number');
}
else{
system.debug('no not a prime number');
}
// displaying numbers from 100 to 1
for(integer i=0;i<100;i++)
{
integer j=100-i;
system.debug(j);
}
SDLC :
1.Planning
2..Designing
3. Building
4. Testing
5. Deploying
Thanks for your time, it's worth reading your post.
ReplyDeleteMove over you made sense in posting some different questions along with answers rather than posting all those Direct questions which were never asked in any interviews.