c# - Obscure "Unsupported overload used for query operator 'Where'."

Question

I'm using LinqPad and LinqKit to try to learn more about linq to construct complex queries, but I seem to be stuck on simple queries. I haven't found a solution to the error in the question description when I input the following -simple- expression:

QHPatients.AsExpandable().Where(p =>
    p.QHEncounters.Where(PredicateBuilder.True<QHEncounter>().Compile()).Any())

If I run the code in VS I get the following error instead: "System.InvalidOperationException : Internal .NET Framework Data Provider error 1025"

Answer 1

p.QHEncounters.Where(PredicateBuilder.True<QHEncounter>().Compile())

在不知道您使用的实际类型的情况下，我猜您将需要调用.AsExpandable()您的调用QHEncounters或省略.Compile()调用。