FetchXml is great when you quickly want to extract some data. Today, I found a weird behaviour, that is either a bug, or a documented “feature” that I am not aware of.
If you run this code below
var fetch = @"
<fetch version='1.0' output-format='xml-platform' mapping='logical' {0} count='1'>
<entity name='contact'>
<attribute name='fullname'/>
</entity>
</fetch>";
Console.WriteLine("With Distinct True And Without Id\n--------------------------------");
var results = crmSvc.OrganizationServiceProxy.RetrieveMultiple(new FetchExpression(string.Format(fetch, "distinct='true'"))).Entities.ToList();
results.ForEach(x => Console.WriteLine("Id: {0}",x.Id));
Console.WriteLine("\nWith Distinct True And With Id Field\n--------------------------------");
results = crmSvc.OrganizationServiceProxy.RetrieveMultiple(new FetchExpression(
@"<fetch version='1.0' output-format='xml-platform' mapping='logical' distinct='true' count='1'>
<entity name='contact'>
<attribute name='contactid'/>
<attribute name='fullname'/>
</entity>
</fetch>")).Entities.ToList();
results.ForEach(x => Console.WriteLine("Id: {0}", x.Id));
Console.WriteLine("\nWith Distinct False\n--------------------------------");
results = crmSvc.OrganizationServiceProxy.RetrieveMultiple(new FetchExpression(string.Format(fetch, "distinct='false'"))).Entities.ToList();
results.ForEach(x => Console.WriteLine("Id: {0}", x.Id));
Console.WriteLine("\nWithout Distinct\n--------------------------------");
results = crmSvc.OrganizationServiceProxy.RetrieveMultiple(new FetchExpression(string.Format(fetch, string.Empty))).Entities.ToList();
results.ForEach(x => Console.WriteLine("Id: {0}", x.Id));
You get this output,
Image may be NSFW.
Clik here to view.
As you can see, if you put distinct=true in your fetchxml, without retrieving the primary key, and iterate through the RetrieveMultiple result, the Id property will be Guid.Empty for all the entities in the EntityCollection.
Image may be NSFW.
Clik here to view.
Image may be NSFW.Clik here to view.
