Salesforce with Ankit

In this article we will discuss about what are triggers in Salesforce? What are their types? and When to use each type of trigger?

1. Introduction –
   • Triggers are special bundles of code that fire whenever an appropriate database action occurs.
   • We can use triggers to allow us to define complex logical processes that occurs whenever a record is changed against Salesforce database.
   • We should look to use trigger-based solution when complex logic is involved that either can not be done in Process Builder / Workflow or require the manipulation of data across multiple disparate objects.
   • Unlike declarative tools, triggers can be fired on deletion and undeletion of records.
2. Types of Apex Triggers –
   • Insert: Runs when creating new record.
   • Update: Run when updating existing record.
   • Delete: Runs when removing a record.
   • Undelete: Runs when reinstating a record from the recycle bin.
   • A trigger can run in either before context or after context.
   • We can not use before context with undelete.
3. When to use each trigger type? –
   • Before Insert:
     • Before insert triggers are first trigger that can run on any record, before record has been assign an Id.
     • We should use before insert trigger to set any values on records we are inserting that are based on complex logic.
     • We can run before insert trigger if we want to implement any complex validation.
   • After Insert:
     • After insert trigger run once the record has been saved to the database and been given an Id.
     • We should use after insert triggers when we either require Id, need to query for some other calculated field value, or want to create or update additional records.
     • We may require Id when creating a series of default child records.
   • Before Update:
     • Before update runs before any changes made to existing records are saved.
     • In this, we have access to both old & new values on the record, that enable us to compare the values and make or validate changes as apppropriate.
   • After Update:
     • After update trigger fires once updates have been written to database and should be used for either creating or updating related records, or when a value from the save is required.
   • Before Delete:
     • Before delete trigger runs before a record is deleted from database and should be used to validate that record should be deleted or not and block delete incase of delete is not needed or possible.
   • After Delete:
     • Once record deletion has saved to the database but not committed, the after delete trigger runs.
     • This trigger-type should be used to clearing related records where cascade delete will not occur.
   • After Undelete:
     • If deleted record is retrieved from recycle bin after it has been resaved to the database, the after delete trigger will fire.
     • This trigger will help us to recreate any relationships or set any value we wish on related records.

Thanks for reading this article till the end. In next article we will discuss about Trigger Context Variables and Bulkification of triggers.