UPDATE .... Default Value in a lookup field

Question

I'd like to create a trigger that automatically assign a value to a lookup field.
I've tried to emulate what I've read on these 3 posts (but without success)

https://developer.salesforce.com/forums?id=906F000000094NcIAI; How to Give Default value to a LookUp field in salesforce; Trigger based on Record Type + Default Value + Lookupfield;

Here is the situation. I have a Product_Sale__c object. Sale_Account__c is a lookup field in that object. That field is looking up for the Name (the Id?) of an account on Account__c. One of the account on Account__c is 'Sales_Revenue'. I'd like that account to be the default one on Sale_Account__c.

Here is what I wrote (after help from Peter Knolle ):

trigger ProductSale_Default_SaleAccount on Product_Sale__c (before insert, before update) {

    Account__c var = [
        SELECT Name 
        FROM Account__c 
        WHERE Name='Sales Revenue'
        ];

    for (Product_Sale__c productsale : trigger.New) {
                    productsale.Sale_Account__c = var.Id;
                    }
}

But nothing the field is still blank on the when I create a new "Product Sale", I was expecting it to already show the 'Sales Revenue' account.

Any advices?

Answer 1

You need to assign the ID (not the Name field) of the ‘Sales Revenue’ Account__c to the productsale.Account__c.

The error that you are getting is because your query queries the Product_Sale__c object but attempts to assign to the Account__c. The object that you query must be assigned to that type of object.

Your query should change to the following:

Account__c defaultSaleAcc = [
    Select Id
    From Account__c
    Where Name = ‘Sales Revenue’
];

Your loop body should change to assign the ID

productsale.Sale_Account__c = defaultSaleAcc.Id;

Lookup fields store the ID of the related record, not the name.

Like @JimRae commented, the trigger fires after the user hits the Save button. If you want the Lookup field pre-populated before the user hits the Save button the only option is a custom Visualforce page or implementing the LKID url hack.

Alternatively, you could check to see if the value has been not been set (i.e., == null) in the trigger and then set it to the default if it hasn't been set. Depending on your business rules you may only want to do that on the initial insert and you could add some help text about the defaulting behavior. Note that this alternative approach doesn't display any value until after the Save.

Answer 2

I am doing the exact thing but on standard Case and Account objects. The problem i am facing is that it gives Null Pointer exception with Attempt to de-reference a null object Trigger.DefaultAccName: line 13, column 1: []

Here is the code i am trying to execute

Account defaultAcc = [SELECT Id FROM Account WHERE Name = 'ABC Support'];

for (Case c: trigger.New) {

  if(c.Type=='Internal')

     {
       c.account.name = defaultAcc.Id;
     }
}

Not able to make out why?

Regards Deepak

Answer 3

Deepak, I think you want to use

c.AccountId = defaultAcc.Id;

instead of trying to update the Name with an Id value....