20 Salesforce Trigger Interview Questions and Answers

Triggers are a powerful tool in Salesforce that can automate processes and improve efficiency in your org. When interviewing for a position that will involve working with Salesforce, it is likely that the interviewer will ask you questions about triggers. Answering these questions confidently can help you demonstrate your knowledge and skills in Salesforce and make a positive impression on the interviewer. In this article, we review some common trigger interview questions and provide tips on how to answer them.

Salesforce Trigger Interview Questions and Answers

Here are 20 commonly asked Salesforce Trigger interview questions and answers to prepare you for your interview:

1. What is a trigger?

A trigger is a piece of code that is executed automatically in response to certain events. Triggers can be written in Apex, and are typically used to perform custom actions when records are created, updated, or deleted.

2. How many triggers can be associated with an object in Salesforce?

There can be up to 10 triggers associated with an object in Salesforce.

3. Can you explain some common use cases for using triggers in Salesforce?

Triggers can be used for a number of different things, but some of the most common use cases include:

– Automatically creating or updating records in Salesforce based on changes in another system
– Enforcing data quality standards by validating data before it is saved to Salesforce
– Sending notifications or emails based on changes in Salesforce data
– Automatically assigning records to users or groups based on certain criteria

4. Are there any limitations to the number of records that can be updated by a single trigger execution? If yes, what are they?

Yes, there are limits to the number of records that can be updated by a single trigger execution. The limit is 100 records for synchronous triggers, and 10,000 records for asynchronous triggers.

5. What do you know about event handlers and Apex classes?

Event handlers are methods that are automatically called by Salesforce when a specific event occurs, such as when a record is created or updated. Apex classes are custom classes that can be written in Salesforce’s Apex programming language. Apex classes can be used to create event handlers.

6. What types of operations can be performed on multiple objects in a single DML statement?

You can perform the following operations on multiple objects in a single DML statement:

-Create
-Update
-Upsert
-Delete

You can also perform these operations on a single object, but it is more efficient to perform them on multiple objects at the same time.

7. Is it possible to execute code after inserting or updating a record if no exceptions were thrown during the update operation? If yes, how?

Yes, it is possible to execute code after inserting or updating a record if no exceptions were thrown during the update operation. This can be done by using the after update trigger.

8. Why should we avoid SOQL queries inside FOR loops?

One of the main reasons to avoid SOQL queries inside FOR loops is because it can lead to governor limits being reached. This can cause your code to fail and can cause performance issues. Additionally, it can make your code more difficult to read and maintain.

9. Can you explain what recursion is?

Recursion is a process where a function calls itself repeatedly until a certain condition is met. In the context of a Salesforce trigger, recursion can occur when a trigger fires and updates a record, which then causes the trigger to fire again (since the record has been updated). This can happen multiple times and can eventually lead to an error if not handled properly.

10. What’s the best way to prevent recursive triggers from executing more than once?

One way to prevent recursive triggers from executing more than once is to use a static variable. When the trigger is fired, the static variable is set to true. If the trigger is fired again while the static variable is still true, then the trigger will not execute.

11. What are the different ways of invoking Apex methods?

There are four ways of invoking Apex methods: from a Visualforce page, from an Apex controller or extension, from a trigger, or from a class that implements an interface.

12. How does a trigger differ from a workflow rule?

A trigger is a piece of code that is executed automatically when a record is inserted, updated, or deleted. A workflow rule, on the other hand, is a set of conditions that are automatically evaluated when a record is created or edited.

13. What happens when a callout is made to an external web service while a trigger is being executed?

When a callout is made to an external web service while a trigger is being executed, the trigger will pause execution until the callout is complete. This can cause delays in the trigger being executed, so it is important to take this into account when designing triggers that make callouts.

14. What is a synchronous vs asynchronous callout?

A synchronous callout is one where the client (in this case, Salesforce) waits for a response from the external service before continuing. This means that if the external service is down, or takes a long time to respond, then the client will be unable to continue. An asynchronous callout is one where the client does not wait for a response from the external service, but instead continues on its own. This means that if the external service is down, or takes a long time to respond, the client will not be affected.

15. What type of exception can be thrown as part of a trigger invocation?

A trigger can throw a System.Exception, which includes a number of different types of exceptions, such as DmlException, QueryException, and EmailException.

16. What is the difference between a trigger context variable and a static variable?

A trigger context variable is a variable that is set by Salesforce and is available to the trigger code. A static variable is a variable that is set by the developer and is only available within the scope of the trigger.

17. Can you give me an example of a situation where a developer needs to write test code to ensure their trigger functions correctly?

A developer would need to write test code to ensure their trigger functions correctly if they were making changes to the trigger that could potentially break its functionality. For example, if a developer were changing the conditions under which the trigger fired, they would need to write test code to make sure that the trigger still fired when it was supposed to and that it didn’t start firing when it wasn’t supposed to.

18. What is a Governor limit? Give me some examples of governor limits.

A Governor limit is a limit placed on the amount of data or number of records that can be processed by a Salesforce trigger. This is done in order to prevent a trigger from overloading the Salesforce system. Some examples of governor limits include the maximum number of records that can be processed by a trigger, the maximum number of characters that can be processed by a trigger, and the maximum number of DML statements that can be processed by a trigger.

19. What are some use cases for writing batchable processes in Salesforce?

Batchable processes can be used for a number of different things, but they are typically used when you need to process a large number of records at once. This could be something like mass emailing a group of users or updating a large number of records at once. Batchable processes can also be used to schedule regular jobs, like nightly data backups or weekly reports.

20. How would you determine if your trigger logic is running efficiently or not?

One way to determine if your trigger logic is running efficiently is to use the Salesforce Developer Console. The Developer Console provides a “Debug Logs” feature that allows you to monitor the execution of your trigger logic. If you see that your trigger is taking a long time to execute, then you can start to optimize your code to improve performance.