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Type:
Bug
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Resolution: Done
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Priority:
Major - P3
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None
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Affects Version/s: 2.2.4
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Component/s: Linq
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Environment:windows
With this query handler
public class AppointmentsFromDateToDateQuery : IQuery<IEnumerable<Appointment>> { public DateTimeOffset From { get; set; } public DateTimeOffset To { get; set; } } public class AppointmentsFromDateToDateQueryHandler : IQueryHandlerAsync<AppointmentsFromDateToDateQuery, IEnumerable<Appointment>> { private IMongoDatabase _db; public AppointmentsFromDateToDateQueryHandler(IMongoDatabase db) { _db = db; } public async Task<IEnumerable<Appointment>> HandleAsync(AppointmentsFromDateToDateQuery query) { return await _db.GetCollection<Appointment>(typeof(Appointment).Name) .Find(a => a.Starts >= query.From && a.Ends <= query.To) .SortBy(a => a.Starts) .ToListAsync(); } and this usage var query = new AppointmentsFromDateToDateQuery() { From = date.Value, To = date.Value.AddDays(1) } ; var items = await new AppointmentsFromDateToDateQueryHandler(_db).HandleAsync(query);
the driver would throw an exception
[InvalidCastException: Object must implement IConvertible.] System.Convert.ChangeType(Object value, Type conversionType, IFormatProvider provider) +14092601 MongoDB.Driver.Linq.Expressions.ISerializationExpressionExtensions.ConvertIfNecessary(Type targetType, Object value) +149 MongoDB.Driver.Linq.Expressions.ISerializationExpressionExtensions.SerializeValue(ISerializationExpression field, Object value) +112 MongoDB.Driver.Linq.Translators.PredicateTranslator.TranslateComparison(Expression variableExpression, ExpressionType operatorType, ConstantExpression constantExpression) +283 MongoDB.Driver.Linq.Translators.PredicateTranslator.Translate(Expression node) +461 MongoDB.Driver.Linq.Translators.PredicateTranslator.TranslateAndAlso(BinaryExpression node) +82 MongoDB.Driver.Linq.Translators.PredicateTranslator.Translate(Expression node) +283 MongoDB.Driver.Linq.Translators.PredicateTranslator.Translate(Expression node, IBsonSerializerRegistry serializerRegistry) +76 MongoDB.Driver.MongoCollectionImpl`1.CreateFindOperation(FilterDefinition`1 filter, FindOptions`2 options) +358 MongoDB.Driver.MongoCollectionImpl`1.FindAsync(FilterDefinition`1 filter, FindOptions`2 options, CancellationToken cancellationToken) +174 MongoDB.Driver.FindFluent`2.ToCursorAsync(CancellationToken cancellationToken) +125 MongoDB.Driver.<ToListAsync>d__16`1.MoveNext() +134 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +13891908 System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +61 System.Runtime.CompilerServices.TaskAwaiter`1.GetResult() +31 Roswell.Plugins.Customers.Queries.<HandleAsync>d__2.MoveNext() +2923 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +13891908 System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +61 System.Runtime.CompilerServices.TaskAwaiter`1.GetResult() +31
Only and only when the collection in question would be empty.
The problem actually lies in the return type of IEnumerable which the driver apparently has a trouble of instantiating.
This is something that normally works with Entity Framework (returning empty IEnumerables).