Attempt to de-reference a null object while calling objects of object value

Question

Below are the objects like Account, Contcat, Object1__c, Object2__c and Object3__c. Each obejct have some different field values like shown below.

Account acc = new Account();
acc.name='Test';
acc.Code__c = '0011';
insert acc;

Contcat con = new Contcat();
con.Lastname='Test_name';
insert con;

Object1__c Obj1 = new Object1__c();
Obj1.Account_ID__c = acc.Id;
Obj1.Contact_ID__c = con.id;
insert Obj1;

Object2__c Obj2 = new Object2__c();
Obj2.Field1__c = 'Test1 Value';
Obj2.Field2__c = 'Test2 Value';
Obj2.Field3__c = 'Test3 Value';
insert Obj2;

Object3__c Obj3 = new Object3__c();
Obj3.Object2__c = Obj2.Id;
Obj3.Object1__c = Obj1.id;

But my issue is, I want to assign a value for the field Code__c using Object3(like shown in below).

Obj3.Object1__c.Account_ID__r.Code__c = 'AAABBB';

It does not give me any issue while saving, but while I am running the code, Its giving bellow error

Attempt to de-reference a null object

Am i missing anything here? Can some one help me here please.

Answer 1

When you are declaring :

Obj3.Object2__c = Obj2.Id;
Obj3.Object1__c = Obj1.Id;

you are associating populating Obj3.Object1__c field with the ID of Obj1. the object has not been inserted and while there is now an id in the Obj3.Object1__c field, the reference to Obj3.Object1__r is still NULL. that is why you are getting this error.

if you were to insert obj3, there would be an Id value in Obj3.Object__c however the reference to Obj3.Object1__r is still NULL.

to accomplish what you are asking for you would need to

1. insert Obj3;

2. query for Obj3 ([Obj3 = SELECT Id, Object1__r.Name FROM Object3__c WHERE Id =: Obj3.Id];

at this point you should be able to read/write to parent fields without getting an error. ex:

update Obj3.Object1__r.Name;

It is still vague the context you are trying to use this in. For simplicity and directness, I would refer to @Aditya or @Radhe answer and just update the account directly:

update acc;

Answer 2

You can not update the parent record field value by writing dml on child record. Try below and this will update account without going into upper hierarchy.

acc.Code__c = 'AAABBB';
update acc;

Answer 3

seems like there is no relationship between object2,object3 with accounts and contacts.

  public static string codevalue;

      Account acc = new Account();
     acc.name='Test';
     acc.Code__c = '0011';

      insert acc;

     codevalue=acc.Code__c;

you can write:

        Obj3.Code__c=codevalue;

or if code__c is gloabl value,declare it and assign it directly to obj.Code__c

Answer 4

You can't assign the values like this.

If you just want to assign the value (for solving the error you mentioned):

Obj3.Object1__r = Obj1;
Obj3.Object1__r.Obj1.Account_ID__r = acc;
Obj3.Object1__r.Obj1.Account_ID__r.Code__c = 'AAABBB';

Or if you want to update the field of parent object, use the parent object in dml operation, not with the child object like:

acc.Code__c = 'AAABBB';
update acc;