I had written a post long back showcasing the aggregate queries on Dynamics CRM on the below link:

https://dynamicsofdynamicscrm.wordpress.com/2014/07/23/aggregate-fetchxml-queries-for-dynamics-crm-20112013/

This is a very performance effective and seldom used piece from most CRM girls and guys out there.

I had got lot of feedback and comments but somehow people were not able to use it in actual code.

So, I had committed to doing a follow-up article with actual reusable code asset. It took a while for

me to come back to this one, but I never break my promises.

So here it goes(The aliased value is Money in my example, it can be decimal and integer as well): 

    public static decimal GetSum(string primaryEntityId, IOrganizationService service)

        {

            string fetchXml = @”<fetch mapping=’logical’ aggregate=’true’ version=’1.0′>” +

                                        “<entity name=’childentityname’>” +

                                         “<attribute name = ‘attributetoadd’ alias=’sum_attributetoadd’ aggregate=’sum’ />” +

                                            “<filter>” +

                                             “<condition attribute = ‘primaryEntityIdfieldname’ operator=’eq’ value='” +

                                                primaryEntityId

                                                + “‘ />” +

                                                “</filter></entity></fetch>”;

            FetchExpression fetch = new FetchExpression(fetchXml);

            EntityCollection result = service.RetrieveMultiple(fetch);

            decimal sum = 0;

            if (result.Entities.Count == 1)

            {

                sum = ((Money)((AliasedValue)(result.Entities[0].Attributes[“sum_attributetosum”])).Value).Value;

            }

            return sum;

        }

 

Hope it helps you and Happy CRMing!