How to retrieve all Opportunity Products for the specific Opportunity through c#?

Question

I have the Opportunity as shown in the below image:

Yesterday, I posted a question on how to create the Opportunity Products (Motor Products) & Dave provided me an answer on how to achieve this.

Now, my requirement has been extended to delete these existing Motor Products & add new products.

I'm thinking to do this by first retrieving all the relative Motor Products from this opportunity.

For creating Opportunity Product I used the below code:

var opportunityProduct = new Entity(entityMotorName);
opportunityProduct["tmeic_opportunitymotorproductid"] = new EntityReference("opportunity", Guid("opportunityid"));
var opportunityProductId = crmService.Create(opportunityProduct);

But, I'm stuck here for retrieing these Motor Products. Once I get the Motor Products which is related to this opportunity I can use the below query.

crmService.Delete(entityName,Guid);

Note: my opportunity has opportunityid but no tmeic_opportunitymotorproductid & my Motor Product (opportunityproduct) doesn't have opportunityid but has tmeic_opportunitymotorproductid.

Only problem is how to retrieve these Motor Products?

Answer 1

Here's one way to do this:

using Microsoft.Xrm.Sdk;
using Microsoft.Xrm.Sdk.Query;
using Microsoft.Xrm.Tooling.Connector;
using System;
using System.Collections.Generic;
using System.Linq;

class App
{
    private IOrganizationService svc;

    public App(IOrganizationService svc)
    {
        this.svc = svc;
    }

    public void Run()
    {
        var list = OppProducts(svc, new Guid("628CF01A-AED1-E411-80EF-C4346BAC7BE8"));
        DeleteList(svc, list);
    }

    public List<Entity> OppProducts(IOrganizationService svc, Guid OppId)
    {
        var query = new QueryExpression
        {
            EntityName = "opportunityproduct",
            ColumnSet = new ColumnSet("tmeic_opportunitymotorproductid", "opportunityproductid"),
            Criteria = new FilterExpression
            {
                FilterOperator = LogicalOperator.And,
                Conditions =
                {
                    new ConditionExpression
                    {
                        AttributeName = "tmeic_opportunitymotorproductid",
                        Operator = ConditionOperator.Equal,
                        Values = { OppId }
                    }   
                }
            }
        };

        var result = svc.RetrieveMultiple(query);

        return result.Entities.ToList();
    }

    public void DeleteList(IOrganizationService svc, List<Entity> list)
    {
        list.ForEach(e => svc.Delete(e.LogicalName, e.Id));
    }
}