Cant retrieve information from table in ASP.NET Entity Framework

See also questions close to this topic

• Filter items in a listbox that have been added with json

  Well I'm trying to list items that are from listbox created with UserControl and the text properties are defined with a json file.

  This is my .json file:

  {
      "Games": {
          "Quantity": 2,
  
          "Title0": "SomeGame1",
          "Description0": "Fps game",
          "Image0": "Some image link",
          "Link0": "GameStore.com/Somegame1",
  
          "Title1": "SomeGame2",
          "Description1": "RPG game",
          "Image1": "Some image link",
          "Link1": "GameStore.com/Somegame2",
      }
  }
  

  This is the code to load the games as items in the listbox:

  string JsonFile =  Environment.CurrentDirectory @"\Test.json";
  dynamic jasonfile = JsonConvert.DeserializeObject(JsonFile);
  
  GameUserControl[] Games = new GameUserControl[jasonfile["Games"]["Quantidade"]];
  
  for (int quantity= 0; quantity < Games.Length; quantity++)
  {
      Games[quantity] = new GameUserControl();
  
      Games[quantity].Descrição.Content = (jasonfile["Games"]["Title" + quantity]);
      Games[quantity].jog = (jasonfile["Games"]["Titulo" + quantity]);
      Games[quantity].lin = (jasonfile["Games"]["Link" + quantity]);
      string image = jasonfile["Games"]["Image" + quantity];
      Games[quantity].imag = new ImageBrush(new BitmapImage(new Uri(image, UriKind.Absolute)));
                 
      GamesListBox.Items.Add(Games[quantity]);
  }
  

  This is the code I used in a textbox to try to filter:

   if (CollectionViewSource.GetDefaultView(GamesListBox.Items) != null)
                      CollectionViewSource.GetDefaultView(GamesListBox.Items).Filter = (o) => { return o.ToString().ToLower().Contains(Search.Text.ToLower()); };
  

  But it didn't work, the item names are always GameUserContro.Can someone help me?
• Advantage of .Net Core over WCF for RESTful APIs

  We are currently using WCF to create RESTful APIs, it is working fine and has an added advantage that it can be consumed via SOAP too if we ever need to. We have all our systems using Microsoft technologies.

  There is no active development on WCF but the current functionality is working fine for us. However, I believe the recommended approach is to start using .Net core for RESTful services. What are the additional advantages .Net core offers over WCF (apart from being platform independent)?
• Generic class type constraint with a generic class having another constraint

  Let's say I have a generic class

  public class G<T> {
  }
  

  and I want to declare final class as

  public class F<T> where T : G<T> {
  }
  

  that seems to be possible, but what if I want to complicate the task and add a constraint to the class G like that

  public class A {
  }
  
  public class DA : A {
  }
  
  public class DB : A {
  }
  
  public class G<T> where T : A {
  }
  

  and finally I want to do this

  public class F<T> where T : G<T> {
  }
  

  that does not work, it says T has to be of type A which is understandable and it looks like I can rewrite it like this

  public class F<T, U> where T : G<U> where U : A {
  }
  

  but in this case the usage has a redundant declaration

  public class DF : F<G<DA>, DA> {
  }
  

  I have to repeat DA twice when using class F even though it is quite clear if I use G as a generic type the generic type of G is DA. Is there a way to avoid this redundancy?
• Cascading databound <ajaxtoolkit:combobox> and <asp:dropdownlist> in asp.net

  I have an asp.net search form that includes an ajaxToolkit Combobox and a standard asp DropDownList. Both controls are bound to two separated SqlDatasource components.

  Something like this:

  <ajaxToolkit:ComboBox
      ID="cbConvenzionato"
      runat="server"
      AutoCompleteMode="SuggestAppend"
      DropDownStyle="DropDownList"
      DataSourceID="sdsConvenzionati"
      DataTextField="nome"
      DataValueField="id"
      AutoPostBack="true"
      OnSelectedIndexChanged="cbConvenzionato_SelectedIndexChanged" />
  
  <asp:DropDownList
      ID="ddlVeicoli"
      DataSourceID="sdsVeicoli"
      DataTextField="targa"
      DataValueField="id"
      runat="server"
      AutoPostBack="true"
      OnSelectedIndexChanged="ddlVeicoli_SelectedIndexChanged"
      AppendDataBoundItems="true">
      <asp:ListItem Text="TUTTI" Value="" Selected="True" />
  </asp:DropDownList>
  
  <asp:SqlDataSource
      ID="sdsConvenzionati"
      runat="server"
      ConnectionString="<%$ ConnectionStrings:db %>"
      ProviderName="<%$ ConnectionStrings:db.ProviderName %>"
      SelectCommand="
          SELECT
              id,
              nome
          FROM
              anag_convenzionati
          ORDER BY nome;" />
  
  <asp:SqlDataSource
      ID="sdsVeicoli"
      runat="server"
      EnableCaching="false"
      CancelSelectOnNullParameter="false"
      ConnectionString="<%$ ConnectionStrings:db %>"
      ProviderName="<%$ ConnectionStrings:db.ProviderName %>"
      SelectCommand="
          SELECT 
              id, 
              targa
          FROM 
              veicoli_contratti
          WHERE
              ((@id_convenzionato IS NULL) OR (id_convenzionato = @id_convenzionato))
          ORDER BY targa;">
      <SelectParameters>
          <asp:ControlParameter
              Name="id_convenzionato"
              ControlID="cbConvenzionato"
              PropertyName="SelectedValue"
              Direction="Input"
              ConvertEmptyStringToNull="true"
              DbType="Int32"
              DefaultValue="" />
      </SelectParameters>
  </asp:SqlDataSource>
  

  There's also a third sqldatasource (sdsNoleggi) that feeds a gridview but this's not a problem right now.

  In code behind I have two event handlers:

      protected void cbConvenzionato_SelectedIndexChanged(object sender, EventArgs e)
      {
          sdsVeicoli.Select(DataSourceSelectArguments.Empty);
  
          Search();
      }
  
      protected void ddlVeicoli_SelectedIndexChanged(object sender, EventArgs e)
      {
          Search();
      }
  
      private void Search()
      {
          sdsNoleggi.Select(DataSourceSelectArguments.Empty);
      }
  

  I tought in this way I should filter ddlVeicoli items after selecting an item in cbConvenzionato... but it's not working... why?

  If I look into sdsVeicoli SelectParameters in debug I can see id_convenzionato being correctly set to selected value (id coming from cbConvenzionato) I bet also that sdsNoleggi dataset wiil be correctly updated with new values since I did this many times before. So why bound control it's not? I tried also to force a ddlVeicoli.DataBind() after sdsVeicoli.Select() call ... but this had no effect.
• Swagger UI not working for REST API (asp.net web api2) application

  I have asp.net mvc project with .NET Framework 4.7.2 and the same project contains asp.net web api2 controller in a separate folder : Controllers. The solution is legacy. The API are already in use in the PRODUCTION environment. Now I added the Swagger nuget package (Install-Package Swashbuckle -Version 5.6.0) to this existing project. Post that I see a SwaggerConfig.cs added to the App_Start folder of the Solution Explorer.

  Here the asp.net mvc controllers are used by App1 pointing to the server: www.app1.com and asp.net web api2 controllers are used by another frontend angular app: App2 pointing to the server : www.app2.com

  The complete deployment package for both App1 and App2 are hosted in IIS

  Any request related to App1 is handled by www.app1.com and any api request related to App2 (Angular frontend) is handled by App1 only using IIS Rewrite rules at App2 level which redirect any api request to App1 only.

  Now in this case when I tried to navigate to www.app1.com/swagger , I see it is loading the SwaggerUI for me, but when I tried to navigate to www.app2.com/swagger it is not working and instead of that it is loading the Angular frontend application

  Here goes the App1 and App2 at IIS level:

  

  Can anyone help me here by providing their guidance to fix this issue?
• Cors error missing allow origin header. MailKit

  I have cors error missing allow origin header error only on ONE post request. My CORS Policy

  public void ConfigureServices(IServiceCollection services)
          {
              services.AddCors(options =>
              {
                  options.AddPolicy("AllowAllOrigins",
                        builder =>
                        {
                            builder.SetIsOriginAllowed(_ => true)
                                    .AllowAnyHeader()
                                    .AllowAnyMethod()
                                    .AllowCredentials();
                        });
              });
  }
  

  Every request work fine, but one POST request fails, it's really weird. Code in controller action which failed use MailKit and SMTP to send email, maybe that's cause
• Trouble with search functionality in ASP.NET Core MVC

  I am trying to add a search functionality to my website. I have managed to add some of the search criteria that i needed however now the data in one of the columns called Departments in not showing for some reason. I think it might be due to there being two tables rather than one. Below is the code for my search function along with a screenshot of my problem.

  Edit1 I have tried implementing lazy include like suggested so here is the code now, I have also attached a picture of my new error.

   public async Task<IActionResult> SList(string search)
          {
              ViewData["GetStudentDetails"] = search;
              var studentquery = from x in _Db.tbl_Student.Include("tbl_Departments") select x;
              
              
              if(!String.IsNullOrEmpty(search))
              {
                  studentquery = studentquery.Where(x => x.FirstName.Contains(search) || x.Email.Contains(search));
                
              }
              return View(await studentquery.AsNoTracking().ToListAsync());
              
              
          }
  

  Edit2 I have also tried writing "Departments" only as suggested but i still get the same error.

  Edit3 Here are the pictures for my tables and my context
• NotMapped property is not supported in Linq?

  I have added RunCount property in class and called in function as below.

   public class ItemsDataObject
   {
          [Key]
          [Column("ID")]
          public string Id{ get; set; }
          .
          .
          .
          [NotMapped]
          public int RunCount { get; set; }
   }
  
  public static List<ItemsDataObject> GetAllItemsWithPaging(int startingPageIndex, int pageSize, string orderColumn, string orderDir)
      {
           using (var ctx = new OracleDbContext())
           {
                List<ItemsDataObject> list = new List<ItemsDataObject>();
      
                var v = (from a in ctx.Items select a);
                v = v.OrderBy(orderColumn + " " + orderDir);
                list = v.Skip(startingPageIndex).Take(pageSize).ToList();
      
                return list;
           }
      }
  

  There are large data in list so i need to firstly sort items and get 10 rows(pagesize) and then .ToList().

  But i am getting System.NotSupportedException error. How can i fix the issue?

  The specified type member 'RunCount' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported.
• EF Core 5 - Update an entity with SQL does not work

  I have an application that use EF Core 5 with SQL Server for production/dev and SQLLite for integration tests.

  In SQL server all works perfectly but with SQLLite in my test my entity is not updated.

  Let's go with some code and explanation.

  Model Buidler

  Here my model builder configuration for my entity :

   modelBuilder.Entity<Order>(order =>
          {
              order.ToTable("Orders");
              order.HasKey(s => s.Id);
              order.Property(i => i.ConcurrencyStamp).IsRowVersion();
              order.Property(i => i.ShippingExcludingTaxes).HasColumnType("decimal(10,2)");
              order.Property(i => i.ShippingIncludingTaxes).HasColumnType("decimal(10,2)");
  
              order.HasMany(s => s.OrderItems).WithOne()
                  .Metadata.PrincipalToDependent.SetPropertyAccessMode(PropertyAccessMode.Field);
              order.Metadata.FindNavigation(nameof(Order.OrderItems)).SetPropertyAccessMode(PropertyAccessMode.Field);
  
              order.HasOne<Payment>(p => p.Payment)
                .WithOne()
                .HasForeignKey<Order>(p => p.PaymentId);
  
              order.HasOne<Address>(s => s.ShippingAddress)
                .WithOne()
                .HasForeignKey<Order>(p => p.ShippingAddressId);
  
              order.OwnsOne(lc => lc.Contact);
  
          });
  

  I already read that RowVersion does not work like in SQLServer, here I use a string generated by a Guid and here the code to update it in each savechanges ( classic & async ):

   private void UpdateLastUpdate()
      {
          var entries = ChangeTracker
                .Entries()
                .Where(e => e.Entity is Entity && (
                        e.State == EntityState.Added
                        || e.State == EntityState.Modified));
  
          foreach (var entityEntry in entries)
          {
              ((Entity)entityEntry.Entity).LastUpdate = DateTime.Now;
              ((Entity)entityEntry.Entity).ConcurrencyStamp = Guid.NewGuid().ToString();
          }
  
      }
  

  Domain class & Tested method

  Here is my entity that I want to update

  public class Order : Entity, IAggregateRoot
      {
          public string UserId { get; set; }
  
          public decimal ShippingIncludingTaxes { get; set; }
          public decimal ShippingExcludingTaxes { get; set; }
  
          public OrderState State { get; set; }
  
          public string PaymentId { get; set; }
          public Payment Payment{ get; set; }
  
          private readonly List<OrderItem> _orderItems = new List<OrderItem>();
          public IReadOnlyCollection<OrderItem> OrderItems => _orderItems;
  
          public string ShippingAddressId { get; set; }
          public Address ShippingAddress { get; set; }
  
          public OrderContact Contact { get; set; }
  
          public ICollection<OrderHistory> OrderHistories { get; set; }
  
          public decimal TotalIncludingTaxes => _orderItems.Sum(s => s.TotalIncludingTaxes) + ShippingIncludingTaxes;
  
  //some other stuff
  }
  

  and the attributes that I am updating In my test

  //method is in Order.cs
       public void SetInProgress(OrderHistory history)
          {
              State = OrderState.InProgress;
              OrderHistories = OrderHistories ?? new List<OrderHistory>();
              OrderHistories.Add(history);
  
          }
  

  Test and assert

  So I run my integration test, all works and I see that my DBContext take my changes. But when It comes to make the assert, the entity is the same before the test

      public class OrderControllerTest : IClassFixture<IntegrationTestFixture>
      {
          private readonly IntegrationTestFixture _fixture;
  
          public OrderControllerTest(IntegrationTestFixture fixture)
          {
              _fixture = fixture;
              Init().GetAwaiter().GetResult();
          }
  
          private IRepository<OrderHistory, UserContext> _orderHistoryRepository;
          private IRepository<Nursery, PlantContext> _nurseryRepository;
          private IRepository<Order, UserContext> _orderRepository;
  
          private Nursery nursery;
          private async Task Init()
          {
              _orderHistoryRepository = _fixture.Services.GetService<IRepository<OrderHistory, UserContext>>();
              _nurseryRepository = _fixture.Services.GetService<IRepository<Nursery, PlantContext>>();
              _orderRepository = _fixture.Services.GetService<IRepository<Order, UserContext>>();
  
              nursery =  await _nurseryRepository.FindAsync(a => a.LegalNumber == NurseryService.LEPAGE_LEGALNUMBER);
          }
  
          [Fact]
          [Trait("Category", "Integration")]
          public async Task OrderController_SendOrders_ShouldBeOkWithOrders()
          {
              await _orderRepository.AddAsync(OrderGenerator.GenerateOrder(OrderState.Validated, nursery.Id));
  
              var result = await _fixture.GetAsync("api/order/send");
  
              result.IsSuccessStatusCode.Should().BeTrue();
  
              var histories = await _orderHistoryRepository.FilterAsync(s => true);
              var orders = await _orderRepository.FilterAsync(s => true);
  
              histories.Should().NotBeEmpty();
              orders.All(all => all.State == OrderState.InProgress).Should().BeTrue();
  
          }
  }
  

  Here when I test if my orders have InProgress state, the result is false because the State is Validated ( the state does not change since the creation ).

  If somebody have an idea ? If the error occurred because of the Guid row version, if any configuration exist to make my test working ?