what is the difference between trigger new amp trigger old

by Jeff Stiedemann Published 3 years ago Updated 2 years ago

Difference between Trigger.new and trigger.old In simple words Trigger.new returns new value of records and Trigger.old returns old value of records. Trigger.new works in case of insert and update both and Trigger.old works in case of update and delete both.

So now we have understood that trigger. newMap returns a new map of records with id and trigger. oldMap returns an old map of records with id.Oct 28, 2019

Full Answer

What is the difference between trigger new and trigger old?

What is the difference between Trigger New & Trigger old? new returns List of new records which are trying to insert into Database. This is available in Before Insert, Before Update, After Insert, After Update Triggers and undelete Triggers. Old: Trigger. old returns List of old records which are updated with new values. Click to see full answer.

What is the use of old trigger in Salesforce?

Trigger.old returns list of old versions of the sObject records.This list available for update and delete triggers. It represents list records already saved in Salesforce. for insertion operation>> there is no trigger.old as there is no existing records.

What is the use of trigger new map?

trigger.newMap just allows you to target specific records by Id should you not need to process everything, or if you need to map other records back to these. Show activity on this post. Let's take following example.

Which list of records can only be modified in before triggers?

This is available in Before Insert, Before Update, After Insert, After Update Triggers and undelete Triggers. This list of records can only modified in Before triggers. Trigger.Old: Trigger.old returns List of old records which are updated with new values. These List of records already there in Database.

What is newMap in trigger?

newMap: Trigger. newMap is a map with key as ID of the record and value as the record itself. Just like the above explanation, in case of accounts when we say trigger. newMap we are talking about a map of key-value pairs where the key is the account ID and the value is the account record itself.

What does trigger old contains?

For an INSERT trigger, OLD contains no values, and NEW contains the new values. For an UPDATE trigger, OLD contains the old values, and NEW contains the new values. For a DELETE trigger, OLD contains the old values, and NEW contains no values.

Can we use newMap in before trigger?

WITH Before Insert, TRIGGER. NEWMAP is not available as we do not have the id of the record generated before the record is inserted, id gets generated when the record is inserted in the database.

Can we use trigger old in before trigger?

No, trigger. old is null in insert triggers.

What is trigger old and trigger oldMap?

Trigger. oldMap - A map of IDs to the old versions of the sObject records. Trigger. newMap - A map of IDs to the new versions of the sObject records.

Why is trigger old read only?

You are getting this error because you are in an after insert trigger and the records are read-only in that context as they have been written, but not committed, to the database. This kind of error occurs if you try to update lists/record which are/is read-only in the trigger execution. For example, trigger.

How and when can we use trigger newMap in a validation trigger?

When to use depends on what you're doing - if you have an ID of an object you need to do something with, using the map makes more sense as you can use newMap. get(). Otherwise, you'd have to loop over all the elements in Trigger. new and look for a matching ID.

What is the order of execution in Salesforce?

Here is an order of execution in salesforce Executes all before triggers. Custom Validation rules. Executes duplicate rules. Saves the record to the database, but doesn't commit yet.

What is the difference between database insert and insert?

Insert – Insert and Database. insert method are same but Database. insert method provide you more flexibility as compared to Insert Method. If there is any exception while making DML using insert then All records will be aborted.

How do I get old values in trigger?

Account oldAccount = Trigger. oldMap. get(acc.ID); //once we get the older version, we can get any field's value from older version to compare.

Can we use trigger old in after delete?

Trigger After Delete Salesforce executes the custom logic after the data is deleted from the Salesforce Database. If you are looking to delete related records, you can make use of Trigger After Delete Salesforce.

What is SObject in Salesforce?

Sobjects are standard or custom objects that stores record data in the force.com database. There is also SObject datatype in apex that is the programmatic representation of these SObjects. Developers referes to SObject and their fields by their API names.

Monday, October 28, 2019

So now we have understood that trigger.new returns new list of records and trigger.old returns old list of records. Let us try to understand the same again by taking an example.

TRIGGER.NEW AND TRIGGER.OLD IN APEX TRIGGER