CRM Plugin IQueryable Early bound Entities subquery is "invoking an invalid property or method"

Question

I have some earlybound entities built with XrmToolbox, using the IQueryable datasets, trying to extract some Case titles where the Case is not linked to another entity. Tried both of these methods and they produce much the same error:

if (cases.Where(x => !serviceContext.new_casegroupSet.Any(y => y.new_case.Id == x.IncidentId)).ToList().Count() > 0)
{
    throw new InvalidPluginExecutionException(OperationStatus.Canceled, 
        $"Case/s missing Groups: \"{(cases.Where(x => !serviceContext.new_casegroupSet.Any(y => y.new_case.Id == x.IncidentId)).Select(x => x.Title).ToList())}\"");
}

and

if (cases.Where(x => serviceContext.new_casegroupSet.Where(y => y.new_case.Id == x.IncidentId).ToList().Count() == 0).ToList().Count() > 0)
{
    throw new InvalidPluginExecutionException(OperationStatus.Canceled, 
        $"Case/s missing Groups: \"{(cases.Where(x => serviceContext.new_casegroupSet.Where(y => y.new_case.Id == x.IncidentId).ToList().Count() == 0).Select(x => x.Title).ToList())}\"");
}

Error is: Invalid 'where' condition. An entity member is invoking an invalid property or method.

Any of these where I'm not nesting a Where() or an Any() seem to work fine, but Any() doesn't actually seem to work at all.

Is this even possible? Or do I have to get the Cases first and iterate through them for matches in the linked entity?

Answer 1

The LINQ to CRM Provider has a lot of limitations where things compile, but don't actually run. I'm assuming nesting those types of statements is one of them. I'd recommend trying to run it as a normal LINQ statement with a Join if you are looking to go that route.

Personally, after trying LINQ to CMR for a couple months, I abandoned it and when to using QueryExpressions where ever possible, creating a whole bunch of extension methods to make them easier to work with. You can feel free to download my nuget library DLaB.Xrm.Source. which simplifies them and removes a lot of it's verbosity.