Npgsq 4.0 with entity Framework 6 - entity-framework

Question

I had a project with ef6 and npgsql 3.2, all worked perfect. But when i updated npgsql to 4.0 and attempt to save entity i got an exception:
"InnerException": {
"ClassName": "System.Data.Entity.Core.UpdateException",
"Message": "An error occurred while updating the entries. See the inner exception for details.",
"Data": null,
"InnerException": {
"ClassName": "System.NotSupportedException",
"Message": "Parameters with NpgsqlDbType.Unknown are no longer supported. If you're writing enums as strings, see the section on unmapped enums in the documentation.",
"Data": null,
"InnerException": null,
"HelpURL": null,
"StackTraceString": " в Npgsql.TypeHandlers.UnknownTypeHandler.ValidateObjectAndGetLength(Object value, NpgsqlLengthCache& lengthCache, NpgsqlParameter parameter)\r\n в Npgsql.NpgsqlParameter.ValidateAndGetLength()\r\n в Npgsql.NpgsqlCommand.ValidateParameters()\r\n в Npgsql.NpgsqlCommand.<ExecuteDbDataReader>d__101.MoveNext()\r\n--- Конец трассировка стека из предыдущего расположения, где возникло исключение ---\r\n в System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n в System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n в System.Data.Entity.Core.Mapping.Update.Internal.DynamicUpdateCommand.<ExecuteAsync>d__0.MoveNext()\r\n--- Конец трассировка стека из предыдущего расположения, где возникло исключение ---\r\n в System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n в System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n в System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.<UpdateAsync>d__0.MoveNext()",
"RemoteStackTraceString": null,
"RemoteStackIndex": 0,
"ExceptionMethod": "8\nValidateObjectAndGetLength\nNpgsql, Version=4.0.0.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7\nNpgsql.TypeHandlers.UnknownTypeHandler\nInt32 ValidateObjectAndGetLength(System.Object, Npgsql.NpgsqlLengthCache ByRef, Npgsql.NpgsqlParameter)",
"HResult": -2146233067,
"Source": "Npgsql",
"WatsonBuckets": null
},
"HelpURL": null,
"StackTraceString": " в System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.<UpdateAsync>d__0.MoveNext()\r\n--- Конец трассировка стека из предыдущего расположения, где возникло исключение ---\r\n в System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n в System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n в System.Data.Entity.Core.Objects.ObjectContext.<ExecuteInTransactionAsync>d__3d`1.MoveNext()\r\n--- Конец трассировка стека из предыдущего расположения, где возникло исключение ---\r\n в System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n в System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n в System.Data.Entity.Core.Objects.ObjectContext.<SaveChangesToStoreAsync>d__39.MoveNext()\r\n--- Конец трассировка стека из предыдущего расположения, где возникло исключение ---\r\n в System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n в System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n в System.Data.Entity.Core.Objects.ObjectContext.<SaveChangesInternalAsync>d__31.MoveNext()",
"RemoteStackTraceString": null,
"RemoteStackIndex": 0,
"ExceptionMethod": "8\nMoveNext\nEntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089\nSystem.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator+<UpdateAsync>d__0\nVoid MoveNext()",
"HResult": -2146233087,
"Source": "EntityFramework",
"WatsonBuckets": null
}
Model code:
[Table("entities")]
public class EntityDto
{
[Column("id")]
[JsonProperty("id")]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public Guid Id { get; set; }
[Column("alias")]
[Index(IsUnique = true)]
public string Alias { get; set; }
[Column("name")]
public string Name { get; set; }
[Column("display")]
public string Display { get; set; }
[Column("dbtable")]
public string DbTable { get; set; }
[Column("assembly")]
public long Assembly { get; set; }
[Column("autogenerated")]
public bool Autogenerated { get; set; }
}
Table of entity was generated perfect by automigration.
At the same time, data selection works correctly.
Whats wrong?

Answer 1

Thanks for reporting this, it's an actual behavior change in Npgsql 4 that didn't take into account the EF6 provider. Can you please open an issue about this on http://github.com/Npgsql/npgsql.
EDIT: Reverted the behavior change, everything should work again in 4.0.0-preview2 which should be released very soon.