ASP.NET Core 2.2，无法确定由实体框架中的导航属性表示的关系

Question

I'm developing an ASP.NET Core 2.2 application that uses Entity Framework Core. I have a one-to-many relationship between OrganismoTransito (parent) and RadicacionCuenta (many). Following is the snippet code according the issue.

Entity Classes:

public partial class RadicacionCuenta
{
    public RadicacionCuenta()
    {
        PropietariosRadicacionesCtas = new HashSet<PropietarioRadicacionCta>();
    }

    public int Id { get; set; }
    public string Placa { get; set; }
    public int IdTipoVehiculo { get; set; }
    public int IdLinea { get; set; }
    public string Modelo { get; set; }
    public string Cilindraje { get; set; }
    public string Tonelaje { get; set; }
    public string Pasajeros { get; set; }
    public string Watts { get; set; }
    public DateTime FechaRegistro { get; set; }
    public DateTime FechaSistema { get; set; }
    public int IdOrganismoTransitoOrigen { get; set; }
    public string EstadoDocumento { get; set; }
    public string DocumentosFaltantes { get; set; }
    public string NumeroFolios { get; set; }
    public DateTime FechaDevolucion { get; set; }
    public string UsuarioDevuelve { get; set; }
    public string EstadoRegistro { get; set; }
    public string MotivoCancelacion { get; set; }
    public string TipoPublico { get; set; }
    public string ValorFactura { get; set; }
    public int IdOrganismoTransitoDestino { get; set; }

    public virtual OrganismoTransito IdOrganismoTransitoDestinoNavigation { get; set; }
    public virtual OrganismoTransito IdOrganismoTransitoOrigenNavigation { get; set; }
    public virtual ICollection<PropietarioRadicacionCta> PropietariosRadicacionesCtas { get; set; }
}

public partial class OrganismoTransito
{
    public OrganismoTransito()
    {
        Blindados = new HashSet<Blindado>();
        Concesionarios = new HashSet<Concesionario>();
        FilialesTransito = new HashSet<FilialTransito>();
        Limitaciones = new HashSet<Limitacion>();
        Polarizados = new HashSet<Polarizado>();
        RadicacionesCuentaIdOrganismoTransitoDestinoNavigations = new HashSet<RadicacionCuenta>();
        RadicacionesCuentaIdOrganismoTransitoOrigenNavigations = new HashSet<RadicacionCuenta>();
        Vehiculos = new HashSet<Vehiculo>();
    }

    public int Id { get; set; }
    public int IdDivisionPolitica { get; set; }
    public string Nombre { get; set; }
    public string Jurisdiccion { get; set; }
    public string Categoria { get; set; }
    public string Abreviatura { get; set; }
    public string DivipoAlterno { get; set; }
    public bool Activo { get; set; }

    public virtual DivisionPolitica IdDivisionPoliticaNavigation { get; set; }
    public virtual ICollection<Blindado> Blindados { get; set; }
    public virtual ICollection<Concesionario> Concesionarios { get; set; }
    public virtual ICollection<FilialTransito> FilialesTransito { get; set; }
    public virtual ICollection<Limitacion> Limitaciones { get; set; }
    public virtual ICollection<Polarizado> Polarizados { get; set; }
    public virtual ICollection<RadicacionCuenta> RadicacionesCuentaIdOrganismoTransitoDestinoNavigations { get; set; }
    public virtual ICollection<RadicacionCuenta> RadicacionesCuentaIdOrganismoTransitoOrigenNavigations { get; set; }
    public virtual ICollection<Vehiculo> Vehiculos { get; set; }
}

I used Fluent configuration in the DbContext 's OnModelCreating , I don't use any annotations. This is the code:

modelBuilder.Entity<RadicacionCuenta>(entity =>
        {
            entity.ToTable("RadicacionesCuentas");

            entity.Property(e => e.Cilindraje)
                .IsRequired()
                .HasMaxLength(10)
                .IsUnicode(false);

            entity.Property(e => e.DocumentosFaltantes)
                .HasMaxLength(250)
                .IsUnicode(false);

            entity.Property(e => e.EstadoDocumento)
                .IsRequired()
                .HasMaxLength(10)
                .IsUnicode(false);

            entity.Property(e => e.EstadoRegistro)
                .IsRequired()
                .HasMaxLength(10)
                .IsUnicode(false);

            entity.Property(e => e.FechaDevolucion).HasColumnType("datetime2(0)");

            entity.Property(e => e.FechaRegistro).HasColumnType("datetime2(0)");

            entity.Property(e => e.FechaSistema).HasColumnType("datetime2(0)");

            entity.Property(e => e.Modelo)
                .IsRequired()
                .HasMaxLength(10)
                .IsUnicode(false);

            entity.Property(e => e.MotivoCancelacion)
                .IsRequired()
                .HasMaxLength(10)
                .IsUnicode(false);

            entity.Property(e => e.NumeroFolios)
                .IsRequired()
                .HasMaxLength(10)
                .IsUnicode(false);

            entity.Property(e => e.Pasajeros)
                .IsRequired()
                .HasMaxLength(10)
                .IsUnicode(false);

            entity.Property(e => e.Placa)
                .IsRequired()
                .HasMaxLength(10)
                .IsUnicode(false);

            entity.Property(e => e.TipoPublico)
                .IsRequired()
                .HasMaxLength(10)
                .IsUnicode(false);

            entity.Property(e => e.Tonelaje)
                .IsRequired()
                .HasMaxLength(10)
                .IsUnicode(false);

            entity.Property(e => e.UsuarioDevuelve)
                .IsRequired()
                .HasMaxLength(10)
                .IsUnicode(false);

            entity.Property(e => e.ValorFactura)
                .HasMaxLength(100)
                .IsUnicode(false);

            entity.Property(e => e.Watts)
                .IsRequired()
                .HasMaxLength(10)
                .IsUnicode(false);

            entity.HasOne(d => d.IdOrganismoTransitoDestinoNavigation)
                .WithMany(p => p.RadicacionesCuentaIdOrganismoTransitoDestinoNavigations)
                .HasForeignKey(d => d.IdOrganismoTransitoDestino)
                .OnDelete(DeleteBehavior.ClientSetNull)
                .HasConstraintName("FK_RadicaCuentas_OTransitoD");

            entity.HasOne(d => d.IdOrganismoTransitoOrigenNavigation)
                .WithMany(p => p.RadicacionesCuentaIdOrganismoTransitoOrigenNavigations)
                .HasForeignKey(d => d.IdOrganismoTransitoOrigen)
                .OnDelete(DeleteBehavior.ClientSetNull)
                .HasConstraintName("FK_RadicaCuentas_OTransitoO");
        });

When I try to run Add-Migration in the Package Manager Console, I get this error:

Add-Migration InitialCreateVehiculosSchema -Context ApplicationDbContext -Project SicotX.Backend.EF -StartupProject SicotX -OutputDir Migrations

System.InvalidOperationException: Unable to determine the relationship represented by navigation property 'OrganismoTransito.RadicacionesCuentaIdOrganismoTransitoDestinoNavigations' of type 'ICollection'. Either manually configure the relationship, or ignore this property using the '[NotMapped]' attribute or by using 'EntityTypeBuilder.Ignore' in 'OnModelCreating'.

at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.PropertyMappingValidationConvention.Apply(InternalModelBuilder modelBuilder)
at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ImmediateConventionScope.OnModelBuilt(InternalModelBuilder modelBuilder)
at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.OnModelBuilt(InternalModelBuilder modelBuilder) at Microsoft.EntityFrameworkCore.Metadata.Internal.Model.Validate() at Microsoft.EntityFrameworkCore.ModelBuilder.FinalizeModel() at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.CreateModel(DbContext context, IConventionSetBuilder conventionSetBuilder, IModelValidator validator) at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.<>c__DisplayClass5_0.b__1() at System.Lazy 1.ViaFactory(LazyThreadSafetyMode mode) at System.Lazy 1.ExecutionAndPublication(LazyHelper executionAndPublication, Boolean useDefaultConstructor) at System.Lazy 1.CreateValue() at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.GetModel(DbContext context, IConventionSetBuilder conventionSetBuilder, IModelValidator validator) at Microsoft.EntityFrameworkCore.Internal.DbContextServices.CreateModel() at Microsoft.EntityFrameworkCore.Internal.DbContextServices.get_Model() at Microsoft.EntityFrameworkCore.Infrastructure.EntityFrameworkServicesBuilder.<>c.<TryAddCoreServices>b__7_2(IServiceProvider p) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor 1.CreateValue() at Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.GetModel(DbContext context, IConventionSetBuilder conventionSetBuilder, IModelValidator validator) at Microsoft.EntityFrameworkCore.Internal.DbContextServices.CreateModel() at Microsoft.EntityFrameworkCore.Internal.DbContextServices.get_Model() at Microsoft.EntityFrameworkCore.Infrastructure.EntityFrameworkServicesBuilder.<>c.<TryAddCoreServices>b__7_2(IServiceProvider p) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor 2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor 2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor 2.VisitCallSite( IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor 2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__0(ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType) at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType) at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider) at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies() at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider() at Microsoft.EntityFrameworkCore.DbContext.Microsoft.EntityFrameworkCore.Infrastructure.IInfrastructure<System.IServiceProvider>.get_Instance() at Microsoft.EntityFrameworkCore.Internal.InternalAccessorExtensions.GetService[TService](IInfrastructure 2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__0(ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType) at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType) at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider) at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies() at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider() at Microsoft.EntityFrameworkCore.DbContext.Microsoft.EntityFrameworkCore.Infrastructure.IInfrastructure<System.IServiceProvider>.get_Instance() at Microsoft.EntityFrameworkCore.Internal.InternalAccessorExtensions.GetService[TService](IInfrastructure 1 accessor) at Microsoft.EntityFrameworkCore.Infrastructure.AccessorExtensions.GetService[TService](IInfrastructure 1 accessor) at Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.CreateContext(Func 1 factory) at Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.CreateContext(String contextType) at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.AddMigration(String name, String outputDir, String contextType) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigrationImpl(String name, Str ing outputDir, String contextType) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigration.<>c__DisplayClass0_1.<.ctor>b__0() at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_0`1.b__0() at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action) Unable to determine the relationship represented by navigation property 'OrganismoTransito.RadicacionesCuentaIdOrganismoTransitoDestinoNavigations' of type 'ICollection'. Either manually configure the relationship, or ignore this property using the '[NotMapped]' attribute or by using 'EntityTypeBuilder.Ignore' in 'OnModelCreating'.

I need help! Thanks

Answer 1

You have need to load to related data using Explicit Loading. You are not post your lambda expression query, so i am make simple lambda expression query using your table. please try the below method you will access parent table data from child table.

using (var context = new dbContext())
{
    var varOrg = context.OrganismoTransito
        .Single(b => b.Id == 1);   


    context.Entry(varOrg)
        .Reference(b => b.RadicacionesCuentaIdOrganismoTransitoDestinoNavigations)
        .Load();
}

For more infomation please read this article. https://docs.microsoft.com/en-us/ef/core/querying/related-data#explicit-loading