Apex Triggers in Salesforce are powerful tools that allow developers to perform custom actions before or after events on records such as insertions, updates, or deletions. They help automate complex business processes by interacting with the Salesforce database in real time.
What is an Apex Trigger?
An Apex Trigger is a piece of code that executes before or after the following types of operations: insert, update, delete, merge, upsert, undelete. They are similar to database triggers in traditional databases but tailored for the Salesforce environment.
Steps to Create an Apex Trigger in Salesforce
If you're new to working with Apex Triggers, you might be unsure where to build them—should it be in a production org or somewhere else? It's strongly advised not to create or test triggers directly in a production environment. Instead, it's best to simulate and test your triggers in a safe, non-live setting.
The ideal environment for experimentation is a sandbox or Developer Edition org. These environments allow you to execute Apex code without affecting your actual Salesforce data.
Most developers prefer using Developer Sandboxes because they offer a flexible and isolated space for rapid development and testing. If a sandbox isn’t available, a Developer Edition org is also a great alternative for hands-on practice.
Let’s walk through creating a simple trigger on the Account object. Follow the steps below:
1. Click the “Setup” icon.
2. Right-click on the “Developer Console” and click “Open link in New Tab.” This way, the developer console opens as a tab in the browser window rather than a new window. This is more convenient to work with.
3. Click “File” -> “New” -> “Apex Trigger”
4. Specify “Name” and select “Object.”
5. Click “Submit.”
Once you have created some triggers, where do you find them? Here are the steps that you can follow:
1. Navigate to set up
2. Type “apex triggers” in the quick find box and click “Apex Triggers” under the Custom code section.
3. The apex Triggers page will open in setup showing you the list of Triggers created so far or the ones that are part of a managed package.
When to Use Apex Triggers?
Use Apex Triggers when:
• You need to enforce complex validation across multiple objects.
• You want to perform asynchronous operations via future methods or queueable.
• You need to automate cascading changes between related records.
• You can't accomplish a business logic using declarative tools like Flows or Process Builder.
Types of Triggers
• Before Triggers – Used to update or validate record values before they’re saved to the database.
• After Triggers – Used to access field values that are set by the system (such as record Ids), and to affect changes in other records.
Trigger Context Variables Explained
Salesforce provides context variables in Triggers to help control the flow and logic based on the event. Here are some key variables:
• Trigger.isInsert – Returns true if the trigger was fired due to an insert operation.
• Trigger.isUpdate – Returns true if it was fired due to an update.
• Trigger.isDelete – Returns true for delete events.
• Trigger.new – Returns a list of the new versions of the sObject records.
• Trigger.old – Returns a list of the old versions of the sObject records.
• Trigger.isBefore – True if the trigger was fired before any record was saved.
• Trigger.isAfter – True if the trigger was fired after all records were saved.
Best Practices
• One Trigger per object.
• Use Trigger Handler Pattern to organize logic.
• Avoid SOQL or DML inside loops.
• Write comprehensive test classes (at least 75% code coverage).
• Use context variables like Trigger.isInsert, Trigger.isUpdate wisely.
Conclusion
Apex Triggers are vital tools for Salesforce developers, enabling automation and business logic implementation that go beyond the capabilities of declarative tools. Understanding when and how to use them ensures cleaner code and better performance across your Salesforce applications.