Примерный код ниже (запрашиваем контакты по GUID родительской организации):
CrmService service = new CrmService();
service.Credentials = System.Net.CredentialCache.DefaultCredentials;
service.Url = "
http://iwexchange:5555/mscrmservices...rmservice.asmx";
ColumnSet cols = new ColumnSet();
cols.Attributes = new string[] {"lastname"};
QueryByAttribute query = new QueryByAttribute();
query.ColumnSet = cols;
query.EntityName = EntityName.contact.ToString();
query.Attributes = new string[] {"parentcustomerid"};
query.Values = new string[] {"{54980211-3238-4D2A-838E-027C95724E18}"};
BusinessEntityCollection retrieved = service.RetrieveMultiple (query);
if (retrieved.BusinessEntities.Length > 0)
{
for (int i=0;i<retrieved.BusinessEntities.Length;i++)
{
contact oContact = new contact();
oContact = (contact)retrieved.BusinessEntities[i];
Console.WriteLine(oContact.lastname.ToString());
}
}