Development questions
In which trigger events are Trigger.old and Trigger.oldMap available?
Trigger.old and Trigger.oldMap are available in before update, after update, before delete, and after delete triggers.
They are not available in insert or undelete triggers because there is no prior version of the record. Both are read-only; attempting to modify them throws an error.
apex-triggertriggercontext-variables
More Development questions
- What is an Apex Trigger in Salesforce and when should you use it over Flows?
- What is the difference between before triggers and after triggers?
- Explain all Trigger context variables (isInsert, isUpdate, isDelete, isUndelete, isBefore, isAfter, isExecuting, size, operationType).
- What is the difference between Trigger.new and Trigger.old?
- In which trigger events are Trigger.new and Trigger.newMap available?
- Why is Trigger.newMap not available in before insert?