First ı want to tell u my architecture.
My tale class for Tale table
public class Tale
{
[ScaffoldColumnAttribute(false)]
public int TaleId { get; set; }
public string TaleName { get; set; }
public string Content { get; set; }
public string VoicePath { get; set; }
public virtual ICollection<Category> Category { get; set; }
}
My category class for Category Table
public class Category
{
public int CategoryId { get; set; }
public string CategoryName { get; set; }
public virtual ICollection<Tale> Tales { get; set; }
}
Like that ı create my TalesCategory table
modelBuilder.Entity<Tale>()
.HasMany<Category>(u => u.Category)
.WithMany(r => r.Tales)
.Map(c => c.ToTable("TalesCategory")
.MapLeftKey("TaleKey")
.MapRightKey("CategoryKey"));
And Its My TaleController:ApiController function
public IEnumerable<Tale> GetAllTales()
{
return TaleService.FindAllTale();
}
My WebApiConfig
config.Formatters.Clear();
config.Formatters.Add(new JsonMediaTypeFormatter());
if I write "/api/tales" ı want to list of my tale but ı take this error. I think I have to write JsonMediaFormatter and I try some code but ı didnt success. What can I do? I use .Net Framework 4.5.
{"Message":"An error has occurred.","ExceptionMessage":"The 'ObjectContent`1' type failed to serialize the response body for content type 'application/json; charset=utf-8'.","ExceptionType":"System.InvalidOperationException","StackTrace":null,"InnerException":{"Message":"An error has occurred.","ExceptionMessage":"Self referencing loop detected with type 'System.Data.Entity.DynamicProxies.Tale_B48C4EAA8B3983ECA938C57C1764611B3C06FAC3348891DAC636EBEBF05EA8E2'. Path '[0].Category[0].Tales'.","ExceptionType":"Newtonsoft.Json.JsonSerializationException","StackTrace":" konum: Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.CheckForCircularReference(JsonWriter writer, Object value, JsonProperty property, JsonContract contract, JsonContainerContract containerContract, JsonProperty containerProperty)\r\n konum: Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IWrappedCollection values, JsonArrayContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)\r\n konum:
You need to break the circular reference that is being picked up because of the navigational property in your EF class.
Try
public IEnumerable<Tale> GetAllTales()
{
return TaleService.FindAllTale().Select(x=> new Tale
{
TaleId = x.TaleId,
TaleName = x.TaleName,
...
});
}
Related
I'm getting this error on one of my fetch services
System.Data.SqlTypes.SqlNullValueException
HResult=0x80131931
Message=Data is Null. This method or property cannot be called on Null
values. Source=Microsoft.Data.SqlClient StackTrace: at
Microsoft.Data.SqlClient.SqlBuffer.get_Int32() at
Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable1.Enumerator.MoveNext() at System.Collections.Generic.List1..ctor(IEnumerable1 collection) at System.Linq.Enumerable.ToList[TSource](IEnumerable1 source) at
Infrastructure.Data.Repository.Base.EfRepository1.List(ISpecification1
spec) in C:\mydir\master\src\DataTier\SMYLS.Data.Respository\Repository\Base\EfRepository.cs:line
88 at
ApplicationCore.Services.Items.ItemService.SearchItems(ItemSearchDataModel
searchModel) in C:\mydir\master\src\ServiceTier\SMYLS.Services\Items\ItemService.cs:line 202 at
Web.Controllers.Api.InvoiceController.GetItemList(ItemSearchDataModel
searchModel) in C:\mydir\master\src\Web\Controllers\Api\InvoiceController.cs:line 322 at
Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.SyncActionResultExecutor.Execute(IActionResultTypeMapper
mapper, ObjectMethodExecutor executor, Object controller, Object[]
arguments) at
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeActionMethodAsync()
at
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State&
next, Scope& scope, Object& state, Boolean& isCompleted) at
Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeNextActionFilterAsync()
This exception was originally thrown at this call stack:
[External Code]
Infrastructure.Data.Repository.Base.EfRepository.List(ApplicationCore.Interfaces.Repository.ISpecification)
in EfRepository.cs
ApplicationCore.Services.Items.ItemService.SearchItems(ApplicationCore.DTOs.Items.ItemSearchDataModel)
in ItemService.cs
Web.Controllers.Api.InvoiceController.GetItemList(ApplicationCore.DTOs.Items.ItemSearchDataModel)
in InvoiceController.cs
[External Code]
This happened after I migrated to net5.0. If I run my netcore3.1, there's no problem at all.
I've researched this error and mostly found errors that were caused when your model is expecting a required property but the database returns a null value. I checked my models but they seem fine (they work on 3.1 without any issue)
these are my model properties
public string Name { get; set; }
public string Description { get; set; }
public decimal Cost { get; set; }
public bool Active { get; set; }
public DateTime UpdatedDateUtc { get; set; }
public int UpdatedBy { get; set; }
public int ClinicId { get; set; }
public int? ServiceGroupId {get;set;}
public string ShortCode { get; set; }
public int? IndustryCodeId { get; set; }
public bool Subscription { get; set; }
public bool BlockBill { get; set; }
public decimal? DiscountPercentage { get; set; }
#nullable enable
public string? SubscriptionType { get; set; }
public virtual Clinic Clinic { get; set; }
public virtual SiteUser UpdatedByNavigation { get; set; }
public virtual ServiceGroup ServiceGroup { get; set; }
public virtual IndustryCode IndustryCode { get; set; }
public virtual ICollection<InvoiceItem> InvoiceItem { get; set; }
public virtual ICollection<DoctorPricing> DoctorPricing { get; set; }
public virtual ICollection<DoctorPricingHistory> DoctorPricingHistory { get; set; }
And these are my sample data from db
Still can't figure out why this is not working in net5.0
On quick glance, I’d suspect the ServiceGroup property, which has a return type of ServiceGroup, but corresponds to a nullable ServiceGroupId column in the database. I’d expect that the return type of the property would need to be ServiceGroup? to allow for nulls.
I’m not certain why that wasn’t throwing an exception in ASP.NET Core 3.x. My suspicion is that ASP.NET Core 5.x does a better job of enforcing nullability of reference types at runtime, thus raising awareness of a long-standing discrepancy in the data model.
In an ASP.NET 3.1 CORE project, using EF, I am trying to implement an object that holds a type of ICollection<Enum> type.
the problem is after reading some tutorials and trying to migrate it to my database something seems off, I will attach screenshots and code for more understanding.
this is the object class :
public class UsersCredentialsModel
{
[Key]
public string UserId { get; set; }
public ICollection<ServiceModel> Services { get; set; }
public string Username { get; set; }
public string Password { get; set; }
public string Hash { get; set; }
}
The ServiceModel class:
public class ServiceModel
{
[Key]
public string ServiceId { get; set; }
public Service Service { get; set; }
}
The Service Enum Class:
public enum Service : int
{
Badoo = 0,
Tinder = 1,
Grinder = 2,
OkCupid = 3
}
This is the AppDbContext class:
public class AppDbContext : IdentityDbContext<ApplicationUser>
{
public AppDbContext(DbContextOptions<AppDbContext> options) : base(options)
{
}
protected override void OnModelCreating(ModelBuilder builder)
{
builder.Entity<Message>().Property(m => m.Service).HasConversion<int>();
builder.Entity<ApplicationUser>().HasMany<Message>(m => m.Messages).WithOne(u =>
u.User).IsRequired();
builder.Entity<ServiceModel>().Property(m => m.Service).HasConversion<int>();
builder.Entity<UsersCredentialsModel>().HasMany(s => s.Services);
base.OnModelCreating(builder);
}
public DbSet<UsersCredentialsModel> UsersCredentialsModels { get; set; }
public DbSet<ServiceModel> ServiceModel { get; set; }
public DbSet<Message> Messages { get; set; }
public DbSet<CookieModel> CookieModel { get; set; }
public DbSet<ProjectionModel> ProjectionModel { get; set; }
}
This is a picture of the UsersCredentialsModel database schema:
** I believe that there should be a filed called "ServiceId" corresponding to the Id of the second table.
and finally a picture of the ServiceModel schema:
from what I understood you can't implement ICollection of type ENUM and you have to wrap it in a class so basically you need an object to hold the ENUM with an ID and another Id that holds the userId.
The problem is that UserCredentialsModel table should hold an Id property of ServiceId coming from ServiceModel table.
because the class has a field of ICollection but when migrating it does nothing
I am working on a new ASP.NET Core 3.1.1 API with Microsoft.AspNetCore.OData v 7.3.0, AutoMapper v9.0.0 and Microsoft.AspNetCore.Mvc.NewtonsoftJson v3.1.1
I am getting the following error when I make a POST to the Accounts endpoint using Postman v7.18.0;
AutoMapper.AutoMapperMappingException: Missing type map configuration or unsupported mapping.
I have reviewed the similar questions list when creating this question but was unable to find a solution.
In reviewing google searches for AutoMapper OData Enums all I could find were the recommendation to decorate my dto class with...
[AutoMap(typeof(Account))]
... and to decorate my dto enum properties with ...
[JsonConverter(typeof(StringEnumConverter))]
However, I still get the error. I found references to using an AutoMapperProfile class with a mapper defined as
CreateMap<Account, AccountModel>().ReverseMap();
But it appears that AutoMapper v9.0.0 no longer has a CreateMap method. My understanding was that adding the [AutoMap(typeof(Account))] to the dto class had the same effect as creating the map in the profile class.
I feel like I am going in circles at this point here so I though I would reach out to the SO community. I am sure it is something simple, I am just not seeing it.
Here is my POST request body from Postman;
{
"#odata.context": "https://localhost:44367/v1/$metadata#Accounts",
"AccountName": "Test Provider",
"AccountType": "Provider",
"IsTaxExempt": false,
"Status": "Active"
}
Here is my AccountsController Post method;
[ODataRoute]
[Produces("application/json;odata.metadata=minimal")]
[ProducesResponseType(typeof(AccountModel), Status201Created)]
[ProducesResponseType(Status400BadRequest)]
public async Task<IActionResult> Post([FromBody] AccountModel record)
{
if (!ModelState.IsValid)
{
return BadRequest(ModelState);
}
record.Id = new Guid();
var entity = _mapper.Map<Account>(record);
_context.Add(entity);
await _context.SaveChangesAsync();
var createdRecord = _mapper.Map<AccountModel>(entity);
return Created(createdRecord);
}
Here is my Account entity class;
public class Account : EntityBase
{
[Required]
[Column(TypeName = "nvarchar(50)")]
[MaxLength(50)]
public string AccountName { get; set; }
public AccountTypes AccountType { get; set; }
public bool IsTaxExempt { get; set; }
}
Here is the EntityBase class;
public class EntityBase
{
[Required]
public Guid Id { get; set; }
public DateTimeOffset? DateTimeCreated { get; set; } = DateTime.UtcNow;
public DateTimeOffset? DateTimeLastModified { get; set; }
[JsonConverter(typeof(StringEnumConverter))]
public StatusTypes Status { get; set; }
public bool DeleteFlag { get; set; }
}
Here is my Account DTO class;
[Filter, Count, Expand, OrderBy, Page, Select]
[AutoMap(typeof(Account))]
public class AccountModel : BaseModel
{
[Required]
[MaxLength(50)]
public string AccountName { get; set; }
[JsonConverter(typeof(StringEnumConverter))]
public AccountTypes AccountType { get; set; }
public bool IsTaxExempt { get; set; }
}
Here is my BaseModel class;
[Select, Filter]
public class BaseModel
{
public Guid Id { get; set; }
public DateTimeOffset DateTimeCreated { get; set; } = DateTime.UtcNow;
public DateTimeOffset DateTimeLastModified { get; set; }
[JsonConverter(typeof(StringEnumConverter))]
public StatusTypes Status { get; set; }
public bool DeleteFlag { get; set; }
}
And here are my Enums for AccountTypes and StatusTypes
public enum AccountTypes
{
Customer = 0,
Reseller = 1,
Provider = 2,
}
public enum StatusTypes
{
Active = 0,
Inactive = 1,
}
Any ideas?
It turns out that I needed to create an instance of an AutoMapper MapperConfiguration and assign it to the mapper.
I ended up putting in in the constructor of the Controller, for example;
public AccountsController(CdContext context, IMapper mapper)
{
_context = context ?? throw new ArgumentNullException(nameof(context));
_mapper = mapper ?? throw new ArgumentNullException(nameof(mapper));
var config = new MapperConfiguration(cfg => cfg.CreateMap<Account, AccountModel>().ReverseMap());
_mapper = new Mapper(config);
}
After I did this, everything worked as expected.
Here is a link to AutoMappers docs on the subject.
First of all, thanks for reading my question.
I am developing a solution using VS 2012 using ADO.NET Entity Framework (5 i think, the latest version). All is working fine until I introduce a WCF service as a Business Layer (this is an assignment for school, I cannot scrap WCF from Business Layer).
The issue is that when I request data from the database. When I have a method that returns a string from the database, it works just fine (since its a primitive). But when it returns an Entity object (Such as Account), it all goes to hell.
Exception: (Yeah, its very vague).
An error occurred while receiving the HTTP response to http://localhost:8733/Services/AccountsManager. This could be due to the service endpoint binding not using the HTTP protocol. This could also be due to an HTTP request context being aborted by the server (possibly due to the service shutting down). See server logs for more details.
What I tried: I tried modifying the Entites.tt file to add the [DataContract] [DataMember] Attribute. This is because in the older versions of EF, it seemed to be doing it on its own. But I do not know if this is neccessary since it allows me to compile and does not complain that it is not serializable.
This is how it looks at first:
namespace CommonLayer
{
using System;
using System.Collections.Generic;
public partial class Account
{
public Account()
{
this.Transactions = new HashSet<Transaction>();
this.Transactions1 = new HashSet<Transaction>();
}
public System.Guid ID { get; set; }
public int Type { get; set; }
public string Name { get; set; }
public int Currency { get; set; }
public decimal Balance { get; set; }
public System.DateTime DateOpened { get; set; }
public Nullable<int> Duration { get; set; }
public string UserName { get; set; }
public virtual AccountType AccountType { get; set; }
public virtual Currency Currency1 { get; set; }
public virtual User User { get; set; }
public virtual ICollection<Transaction> Transactions { get; set; }
public virtual ICollection<Transaction> Transactions1 { get; set; }
}
}
How it looks after modification:
namespace CommonLayer
{
using System;
using System.Collections.Generic;
using System.Runtime.Serialization;
[DataContract] public partial class Account
{
public Account()
{
this.Transactions = new HashSet<Transaction>();
this.Transactions1 = new HashSet<Transaction>();
}
[DataMember] public System.Guid ID { get; set; }
[DataMember] public int Type { get; set; }
[DataMember] public string Name { get; set; }
[DataMember] public int Currency { get; set; }
[DataMember] public decimal Balance { get; set; }
[DataMember] public System.DateTime DateOpened { get; set; }
[DataMember] public Nullable<int> Duration { get; set; }
[DataMember] public string UserName { get; set; }
public virtual AccountType AccountType { get; set; }
public virtual Currency Currency1 { get; set; }
public virtual User User { get; set; }
public virtual ICollection<Transaction> Transactions { get; set; }
public virtual ICollection<Transaction> Transactions1 { get; set; }
}
}
Any pointers are greatly appreciated.
My WCF Class
using System;
using System.Collections.Generic;
using System.Linq;
using System.ServiceModel;
using System.Text;
using System.Threading.Tasks;
namespace BusinessLayer
{
[ServiceContract]
interface IAccountsManager
{
[OperationContract]
List<CommonLayer.Account> GetAccounts(String UserName);
[OperationContract]
String GetData();
[OperationContract]
CommonLayer.Account GetAccount(String UserName);
}
class AccountsManager: IAccountsManager, IDisposable
{
public List<CommonLayer.Account> GetAccounts(String UserName)
{
return DataLayer.AccountsRepository.Instance.GetAccountList(UserName).ToList();
}
public String GetData()
{
CommonLayer.Account acc = this.GetAccounts("test").FirstOrDefault();
return acc.DateOpened.ToString();
}
public CommonLayer.Account GetAccount(String UserName)
{
return this.GetAccounts(UserName).FirstOrDefault();
}
public void Dispose()
{
DataLayer.AccountsRepository.Reset();
}
}
}
You need to use a DTO (Data Transfer Object) and map from your EF object to your DTO.
So the service might accept an object called MyDto looking like:
[DataContract]
public class MyDto {
[DataMember]
public int Id {get;set;}
}
and a static mapping class with methods
public static MyEntity Map(MyDto dto) {
return new MyEntity { Id = dto.Id };
}
public static MyDto Map(MyEntity entity) {
return new MyDto { Id = entity.Id };
}
You can then map as required so that the service can use the DTO and Entity Framework can use the Entity.
It seems that when the EF class has Navigation properties (like ICollection<Transaction> Transactions in your class) it will fails when being transferred over WCF.
After many searches I could not find any solution except mapping an EF class into equivalent DTO class that is exactly the same as the EF class except the Navigation propertis and the constructor (i.e. I have stripped all virtual propertis (like ICollection ones) and the ctor from the EF class and have created from that a new class called the same as my EF class plus Dto suffix (e.g. CustomerDto).
I've used AutoMapper to automatically map an EF object into Dto-equivalent one. E.g:
var customer = getCustomer(cid);
var customerDto = Mapper.Map<CustomerDto>(customer);
return customerDto;
My WCF contract includes
[OperationContract]
CustomerDto getCustomerData(int cid);
In addition I needed to do one time initialization of the Mapper. I've done it within Global.asax as follows:
Mapper.CreateMap<Customer, CustomerDto>();
What I have done is changed my Entities.Edmx file. Firstly, I deleted all (2) ".tt" files. Then i changed Code Generation Strategy from None to Default. This seemed to solve all my problems.
When I return IEnumerable<ProgramRange> an exception is thrown:
The underlying connection was closed: The connection was closed unexpectedly.
The class ProgramRange looks like this:
[DataContract]
public partial class ProgramRange
{
public ProgramRange()
{
this.GradeVariants = new HashSet<GradeVariant>();
}
[DataMember]
public int ID { get; set; }
[DataMember]
public int Range { get; set; }
[DataMember]
public string Description { get; set; }
[DataMember]
public virtual ICollection<GradeVariant> GradeVariants { get; set; }
}
The collection only contains eight items, so I don't think it's the <dataContractSerializer maxItemsInObjectGraph="2147483647" /> which is often suggested.
When I fetch the data from the context I do .ToList() so it can't be that:
public IEnumerable<ProgramRange> GetAll()
{
using (Entities dbContext = new Entities())
{
return dbContext.ProgramRanges.ToList();
}
}
I've tried to add the ProgramRange class to the known types of your service in the implementation:
[ServiceBehavior]
[ServiceKnownType(typeof(ProgramRange))]
public class ValidationService : IValidationService
I've tried returning several other things just to test: ProgramRange (works), IEnumerable<string> (works), List<ProgramRange> (does't work)
I know there are several question on the subject here on stackowerflow and I tried a lot of suggestions, but I can't get it to work.
Edit:
Here's the GradeVariant class:
[DataContract]
public partial class GradeVariant
{
public GradeVariant()
{
this.GradeVariantRules = new HashSet<GradeVariantRule>();
}
[DataMember]
public int ID { get; set; }
[DataMember]
public int GradeTypeID { get; set; }
[DataMember]
public int ProgramRangeID { get; set; }
[DataMember]
public Nullable<int> ProgramID { get; set; }
[DataMember]
public Nullable<int> ApprenticeID { get; set; }
[DataMember]
public Nullable<int> Prefix { get; set; }
[DataMember]
public Nullable<bool> IV { get; set; }
[DataMember]
public string Description { get; set; }
[DataMember]
public virtual GradeType GradeType { get; set; }
[DataMember]
public virtual ProgramRange ProgramRange { get; set; }
[DataMember]
public virtual ICollection<GradeVariantRule> GradeVariantRules { get; set; }
}
Edit :
You are using nullable objects, this is not allowed in a wcf service.
Add [IgnoreDataMember] in front of these members or make them not nullable to fix your issue.
Could you post the class GradeVariant as well? It's possible there are certain unparsable elements in that class which throw the connection was closed unexpectedly.
A few posibilities are a dictionary or nullable item.
Your test with a single ProgramRange might work because the list of GradeVariants is empty or null.
A good tip to try out is to check the inner exception of the inner exception of the inner exception....
At the end of the line it usually says something like can't parse Dictionary.
If it's the serialization (which it probably is), try this more directly to see if you can find the issue:
try
{
MemoryStream tempWrite = new MemoryStream();
DataContractSerializer ds = new DataContractSerializer(typeof(ProgramRange));
ds.WriteObject(myProgramRangeInstance, tempWrite);
MemoryStream tempRead = new MemoryStream(tempWrite.GetBuffer());
ProgramRange newInstance = (ProgramRange)ds.ReadObject(tempRead);
}
catch(Exception ex)
{
Console.WriteLine(ex.ToString());
}
Try that with myProgramRangeInstance starting out as a valid instance of your class. That'll tell you if it's a serialization issue, and what exactly is causing it.
Right now, I'm betting on the fact that you're using a HashSet, but I really don't know. The exception information from the above should give more information.
I found the answer to my own question and here goes:
The problem was that WCF was unable to serialize the circular reference that Entity Framework created when loading the referenced entities.
To resolve this issue, simply put
[DataContract(IsReference = true)]
over the model class.
It's explained in detail here, http://www.binaryforge-software.com/wpblog/?p=129