[SalesForce] Issue with Quote Line items

Assuming that you can use a formula to concatenate the product code and quote code you can do this without any custom code.

• Add a custom text field for users to enter the quote portion of the code and add it to your multi-line layout.
• Create a formula to concatenate the product code and the quote code the users have entered: Product2.ProductCode + quote_code__c

I would recommend using the standard ProductCode field to store the "production code" as you cannot add custom product fields to the quote item multi-line layout.

If you need the full concatenated code to remain the same when the product code changes you can just change this to a workflow rule that runs on create.

As the error states, you need to specify the opportunity id. Presumably, you'll find the opportunity attached to the order.

That probably looks like this:

trigger CreateOpportunityProduct on Order_Line_Item__c(after insert, after update){       
if(trigger.isUpdate)
{          
    map<id, order__c> orders = new map<id, order__c>();
List<ID> pricebookID=new List<ID>();       
List<ID> opportunityID=new List<ID>();           
List<OpportunityLineItem> newopportunitylineitemlist=new List< OpportunityLineItem>();        
    for(order_line_item__c record: trigger.new) {
        orders.put(record.order__c, null);
    }
    orders.putall([select id, opportunity__c from order__c where id in :orders.keyset()]);
for(Order_Line_Item__c orderlist: Trigger.new){    
OpportunityLineItem Oppitem=new OpportunityLineItem();
Oppitem.Quantity=orderlist.Quantity__c;
Oppitem.UnitPrice=orderlist.UnitPrice__c;
oppitem.opportunityid = orders.get(orderlist.order__c).opportunity__c;
pricebookID.add(Oppitem.PriceBookEntryId);
opportunityID.add(Oppitem.OpportunityId);
newopportunitylineitemlist.add(Oppitem);
}    
List<Order__c> orderlist= new List<Order__c>([Select Id,Opportunities__c From Order__c Where Opportunities__c IN:opportunityID]);            
List<PricebookEntry> pricebookentrylist = new List<PricebookEntry>([Select Id,Product2Id From PricebookEntry Where Id IN:pricebookID]);         
if(newopportunitylineitemlist.size()>0)
insert(newopportunitylineitemlist);    
}    
}

Adjust field names as necessary.