我正在尝试升级Web API以使用OData V4查询语法。升级后，dll可以对我的Web api发出$filter和$select查询。
但是当我发出诸如https://localhost:65000/api/Entitlement?$apply=groupby((Grade))之类的请求时，低于异常（上午使用NHibernate ORM）
{
"message": "An error has occurred.",
"exceptionMessage": "MemberInitExpression",
"exceptionType": "System.NotSupportedException",
"stackTrace": " at NHibernate.Linq.Visitors.HqlGeneratorExpressionTreeVisitor.VisitExpression(Expression expression)\r\n at NHibernate.Linq.Visitors.ResultOperatorProcessors.ProcessGroupBy.<>c__DisplayClass1.<Process>b__0(Expression k)\r\n at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext()\r\n at System.Linq.Buffer`1..ctor(IEnumerable`1 source)\r\n at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)\r\n at NHibernate.Linq.Visitors.ResultOperatorProcessors.ProcessGroupBy.Process(GroupResultOperator resultOperator, QueryModelVisitor queryModelVisitor, IntermediateHqlTree tree)\r\n at NHibernate.Linq.Visitors.ResultOperatorProcessors.ResultOperatorProcessor`1.Process(ResultOperatorBase resultOperator, QueryModelVisitor queryModel, IntermediateHqlTree tree)\r\n at NHibernate.Linq.Visitors.ResultOperatorProcessors.ResultOperatorMap.Process(ResultOperatorBase resultOperator, QueryModelVisitor queryModel, IntermediateHqlTree tree)\r\n at NHibernate.Linq.Visitors.QueryModelVisitor.VisitResultOperator(ResultOperatorBase resultOperator, QueryModel queryModel, Int32 index)\r\n at Remotion.Linq.Clauses.ResultOperatorBase.Accept(IQueryModelVisitor visitor, QueryModel queryModel, Int32 index)\r\n at Remotion.Linq.QueryModelVisitorBase.VisitResultOperators(ObservableCollection`1 resultOperators, QueryModel queryModel)\r\n at Remotion.Linq.QueryModelVisitorBase.VisitQueryModel(QueryModel queryModel)\r\n at NHibernate.Linq.Visitors.QueryModelVisitor.GenerateHqlQuery(QueryModel queryModel, VisitorParameters parameters, Boolean root)\r\n at NHibernate.Linq.NhLinqExpression.Translate(ISessionFactoryImplementor sessionFactory)\r\n at NHibernate.Hql.Ast.ANTLR.ASTQueryTranslatorFactory.CreateQueryTranslators(String queryIdentifier, IQueryExpression queryExpression, String collectionRole, Boolean shallow, IDictionary`2 filters, ISessionFactoryImplementor factory)\r\n at NHibernate.Engine.Query.QueryPlanCache.GetHQLQueryPlan(IQueryExpression queryExpression, Boolean shallow, IDictionary`2 enabledFilters)\r\n at NHibernate.Impl.AbstractSessionImpl.GetHQLQueryPlan(IQueryExpression queryExpression, Boolean shallow)\r\n at NHibernate.Impl.AbstractSessionImpl.CreateQuery(IQueryExpression queryExpression)\r\n at NHibernate.Linq.DefaultQueryProvider.PrepareQuery(Expression expression, IQuery& query, NhLinqExpression& nhQuery)\r\n at NHibernate.Linq.DefaultQueryProvider.Execute(Expression expression)\r\n at NHibernate.Linq.DefaultQueryProvider.Execute[TResult](Expression expression)\r\n at Remotion.Linq.QueryableBase`1.System.Collections.IEnumerable.GetEnumerator()\r\n at System.Linq.Enumerable.<OfTypeIterator>d__95`1.MoveNext()\r\n at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)\r\n at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)\r\n at MatrixGroup.Bmx.Server.Filters.UnitOfWorkFilterAttribute.OnActionExecuted(HttpActionExecutedContext actionExecutedContext)\r\n at System.Web.Http.Filters.ActionFilterAttribute.OnActionExecutedAsync(HttpActionExecutedContext actionExecutedContext, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Filters.ActionFilterAttribute.<CallOnActionExecutedAsync>d__5.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Filters.ActionFilterAttribute.<ExecuteActionFilterAsyncCore>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Filters.AuthorizationFilterAttribute.<ExecuteAuthorizationFilterAsyncCore>d__2.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Controllers.ExceptionFilterResult.<ExecuteAsync>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Web.Http.Controllers.ExceptionFilterResult.<ExecuteAsync>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()"
}