How to Write a Basic Trigger in lightning-salesforce

How to Write a Basic Trigger in Salesforce

Triggers in Salesforce are pieces of Apex code that execute before or after specific database-related events, such as insert, update, delete, or undelete operations on records. Let's explore some scenarios and examples of basic triggers written in Salesforce:

Scenario 1: Before Insert Trigger

In this scenario, we'll create a trigger that executes before inserting a new Account record and sets a default value for the Account's Industry field. Let's see the code:

    
trigger SetDefaultIndustry on Account (before insert) {
    for (Account acc : Trigger.new) {
        acc.Industry = 'Technology';
    }
}
    
  

To test the trigger, follow these steps:

1. Create a new Account record in Salesforce.
2. Set any desired values for other fields, such as Account Name, Industry, etc.
3. Save the record.

The trigger will automatically execute before the Account record is inserted, and the Industry field will be set to 'Technology'.

Scenario 2: After Update Trigger

In this scenario, we'll create a trigger that executes after updating an Opportunity record and displays a debugging result. Here's the code:

    
trigger DebugOnOpportunityUpdate on Opportunity (after update) {
    for (Opportunity opp : Trigger.new) {
        Opportunity oldOpp = Trigger.oldMap.get(opp.Id);
        
        if (opp.StageName == 'Closed Won' && oldOpp.StageName != 'Closed Won') {
            System.debug('Opportunity ID: ' + opp.Id + ' has changed to Closed Won stage.');
        }
    }
}
    
  

To test the trigger, follow these steps:

1. Update an existing Opportunity record in Salesforce.
2. Change the Stage field to 'Closed Won'.
3. Save the record.

After the update, check the Debug Logs in Salesforce to see the debugging result generated by the trigger.

Debugging Result:

Opportunity ID: [Opportunity ID] has changed to Closed Won stage.