Copy value from another object before insert

Question

i have 2 custom fields named color__c in the object Case and Account, before i create a case, i would like to copy the value in Account.color__c to Case.color__c in the trigger before inserting whitout creating a formula field, just by calling a copyColorField method and using the accountId relationship, i would like to know if it's possible without using another soql in the after insert trigger for exemple ?

public static void copyColorField(List<Case> caseListToEdit){
    

}


// exemple with two accounts having black and red color value in color__c field
Case c1 = new case(Subject = 'Test 1', AccountId = '0011l0000101uM9854');
Case c2 = new case(Subject = 'Test 2', AccountId = '0011l0000101uM9844');
Case [] inputCases = new case[]{c1,c2};
insert inputCases; 

// expected result after insert
--> Case:{Subject='Test 1', AccountId=0011l0000101uM9854, color__c='black'}, Case:{Subject='Test 2', AccountId=0011l0000101uM9844, color__c='red'}

Answer 1

i would like to know if it's possible without using another soql in the after insert trigger for exemple ?

No.

A trigger only includes the field values of the record you're on, not any records it links to. To get values off parent records, you have to perform a SOQL.

If you want to avoid a SOQL query, you'll need to use a formula field. You can have a formula field on the case that you can use in the trigger to populate a text field.

BTW, this is logic you'll want to perform in a before trigger, not an after trigger.