Apex Developer Guide

Apex Developer Guide
Release Notes
Getting Started with Apex
Writing Apex
Running Apex
Invoking Apex
Anonymous Blocks
Triggers
Bulk Triggers
Trigger Syntax
Trigger Context Variables
Context Variable Considerations
Common Bulk Trigger Idioms
Defining Triggers
Triggers and Merge Statements
Triggers and Recovered Records
Triggers and Order of Execution
Operations That Don't Invoke Triggers
Entity and Field Considerations in Triggers
Triggers for Chatter Objects
Trigger Considerations for Knowledge Articles
Trigger Exceptions
Trigger and Bulk Request Best Practices
Asynchronous Apex
Exposing Apex Methods as SOAP Web Services
Exposing Apex Classes as REST Web Services
Apex Email Service
Using the InboundEmail Object
Visualforce Classes
JavaScript Remoting
Apex in AJAX
Apex Transactions and Governor Limits
Using Salesforce Features with Apex
Integration and Apex Utilities
Debugging, Testing, and Deploying Apex
Apex Reference
Appendices
PDF

Note: This release is in preview. Features described here don’t become generally available until the latest general availability date that Salesforce announces for this release. Before then, and where features are noted as beta, pilot, or developer preview, we can’t guarantee general availability within any particular time frame or at all. Make your purchase decisions only on the basis of generally available products and features.

Trigger Exceptions

Triggers can be used to prevent DML operations from occurring by calling the addError() method on a record or field. When used on Trigger.new records in insert and update triggers, and on Trigger.old records in delete triggers, the custom error message is displayed in the application interface and logged.

Users experience less of a delay in response time if errors are added to before triggers.

Note

A subset of the records being processed can be marked with the addError() method:
  • If the trigger was spawned by a DML statement in Apex, any one error results in the entire operation rolling back. However, the runtime engine still processes every record in the operation to compile a comprehensive list of errors.
  • If the trigger was spawned by a bulk DML call in the Lightning Platform API, the runtime engine sets aside the bad records and attempts to do a partial save of the records that did not generate errors. See Bulk DML Exception Handling.

If a trigger ever throws an unhandled exception, all records are marked with an error and no further processing takes place.