sf-skills

# Salesforce Apex Trigger for Opportunity Stage Update

```java
trigger OpportunityStageTrigger on Opportunity (after update) {
    List<Opportunity> opportunitiesToUpdate = new List<Opportunity>();
    
    for (Opportunity opp : Trigger.new) {
        if (opp.StageName != Trigger.oldMap.get(opp.Id).StageName) {
            // Update related records based on new stage
            if (opp.StageName == 'Negotiation/Review') {
                opp.Description = 'Negotiation started: ' + System.today();
                opportunitiesToUpdate.add(opp);
            }
            // Add more stage-specific logic as needed
        }
    }
    
    if (!opportunitiesToUpdate.isEmpty()) {
        update opportunitiesToUpdate;
    }
}
```

## Explanation

This Apex trigger monitors changes to the Opportunity Stage field. When an opportunity moves to the 'Negotiation/Review' stage:
- It updates the Description field to note the negotiation start date
- The trigger only fires when the stage actually changes (not on initial creation)
- It processes updates in bulk to optimize performance

## Next Steps

1. Test this trigger in a sandbox environment
2. Consider adding error handling for specific business rules
3. Review governor limits to ensure compliance with Salesforce's execution limits