错误：实体类型需要定义主键

时间：2018-10-31 20:47:41

标签： c# .net asp.net-core entity-framework-core

我正在尝试遵循有关Entity Framework Core的一些教程。本教程采用代码优先的方法来创建数据库。当我尝试运行第一次迁移时，此错误显示：

  

实体类型“值”要求定义主键。

确切的消息如下：

  

System.InvalidOperationException：实体类型“值”需要一个   要定义的主键。在   Microsoft.EntityFrameworkCore.Infrastructure.ModelValidator.ValidateNonNullPrimaryKeys（IModel   型号）   Microsoft.EntityFrameworkCore.Infrastructure.ModelValidator.Validate（IModel   型号）   Microsoft.EntityFrameworkCore.Infrastructure.RelationalModelValidator.Validate（IModel   型号）   Microsoft.EntityFrameworkCore.Internal.SqliteModelValidator.Validate（IModel   型号）   Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.CreateModel（DbContext   上下文，IConventionSetBuilder ConventionSetBuilder，IModelValidator   验证者）   Microsoft.EntityFrameworkCore.Infrastructure.ModelSource。<> c__DisplayClass5_0.b__1（）   在System.Lazy 1.ViaFactory(LazyThreadSafetyMode mode) at System.Lazy 1.ExecutionAndPublication（LazyHelper   executionAndPublication，布尔值useDefaultConstructor）   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_1(IServiceProvider p) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor 2.VisitCallSite（IServiceCallSite   callSite，TArgument参数）在   Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped（ScopedCallSite   scopedCallSite，ServiceProviderEngineScope范围）   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参数）在   Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped（ScopedCallSite   scopedCallSite，ServiceProviderEngineScope范围）   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 1   访问者）   Microsoft.EntityFrameworkCore.Infrastructure.AccessorExtensions.GetService [TService]（IInfrastructure 1 accessor) at Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.CreateContext(Func 1   工厂）   Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.CreateContext（String   contextType）   Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.AddMigration（String   名称，字符串outputDir，字符串contextType）位于   Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigrationImpl（String   名称，字符串outputDir，字符串contextType）位于   Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigration。<> c__DisplayClass0_1。<。ctor> b__0（）   在   Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase。<> c__DisplayClass3_0`1.b__0（）   在   Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute（操作   操作），实体类型“值”需要定义一个主键。

（有人可以编辑此味精，因为它看起来很糟糕，我无法修复？）

我已经仔细检查了我在 Value 类中是否具有 Id 属性，并且为了确定自己添加了[Key]。 我还重新启动了笔记本电脑，这可能与以前的测试会话中运行的服务器实例有关。

我的模型班：

using System.ComponentModel.DataAnnotations;

namespace DatingApp.API.Models
{
    public class Value
    {
        [Key]
        public int Id { get; set; }
        public string Name { get; set; } 
    }
}

DbContext：

using DatingApp.API.Models;
using Microsoft.EntityFrameworkCore;

namespace DatingApp.API.Data
{
    public class DataContext : DbContext
    {
        public DataContext(DbContextOptions<DataContext> options) : base (options) {}

        public DbSet<Value> Values {get; set;}
    }
}

Startup.cs 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using DatingApp.API.Data;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;

namespace DatingApp.API
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;

        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddDbContext<DataContext>(c => c.UseSqlite(Configuration.GetConnectionString("DefaultConnection")));
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
               // app.UseHsts();
            }

            // app.UseHttpsRedirection();
            app.UseMvc();
        }
    }
}

和连接字符串：

{
  "ConnectionStrings":
  {
    "DefaultConnection": "Data Source=DatingApp.db"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "AllowedHosts": "*"
}

我在终端上写的东西：

dotnet ef migrations add InitialMigration

编辑：

D:\DatingApp\DatingApp.API>dotnet ef migrations add InitialMigration -v
Using project 'D:\DatingApp\DatingApp.API\DatingApp.API.csproj'.
Using startup project 'D:\DatingApp\DatingApp.API\DatingApp.API.csproj'.
Writing 'D:\DatingApp\DatingApp.API\obj\DatingApp.API.csproj.EntityFrameworkCore.targets'...
dotnet msbuild /target:GetEFProjectMetadata /property:EFProjectMetadataFile=C:\Users\B590\AppData\Local\Temp\tmp24D5.tmp
     

/ verbosity：quiet / nologo   D：\ DatingApp \ DatingApp.API \ DatingApp.API.csproj       编写'D：\ DatingApp \ DatingApp.API \ obj \ DatingApp.API.csproj.EntityFrameworkCore.targets'...       dotnet msbuild / target：GetEFProjectMetadata /property:EFProjectMetadataFile=C:\Users\B590\AppData\Local\Temp\tmp2B8C.tmp   / verbosity：安静/ nologo   D：\ DatingApp \ DatingApp.API \ DatingApp.API.csproj       dotnet版本D：\ DatingApp \ DatingApp.API \ DatingApp.API.csproj / verbosity：quiet / nologo 

Compilation succesfull.
    Warnings: 0
    Errors: 0

Time passed: 00:00:02.25
dotnet exec --depsfile D:\DatingApp\DatingApp.API\bin\Debug\netcoreapp2.1\DatingApp.API.deps.json
     

-additionalprobingpath C：\ Users \ B590.nuget \ packages --additionalprobingpath“ C：\ Program Files \ dotnet \ sdk \ NuGetFallbackFolder” --runtimeconfig   D：\ DatingApp \ DatingApp.API \ bin \ Debug \ netcoreapp2.1 \ DatingApp.API.runtimeconfig.json   “ C：\ Program   文件\ dotnet \ sdk \ 2.1.403 \ DotnetTools \ dotnet-ef \ 2.1.4 \ tools \ netcoreapp2.1 \ any \ tools \ netcoreapp2.0 \ any \ ef.dll”   迁移添加InitialMigration --assembly   D：\ DatingApp \ DatingApp.API \ bin \ Debug \ netcoreapp2.1 \ DatingApp.API.dll   --startup-assembly D：\ DatingApp \ DatingApp.API \ bin \ Debug \ netcoreapp2.1 \ DatingApp.API.dll   --project-dir D：\ DatingApp \ DatingApp.API \-语言C＃--working-dir D：\ DatingApp \ DatingApp.API --verbose --root-namespace DatingApp.API       使用程序集“ DatingApp.API”。       使用启动程序集“ DatingApp.API”。       使用应用程序基础'D：\ DatingApp \ DatingApp.API \ bin \ Debug \ netcoreapp2.1'。       使用工作目录“ D：\ DatingApp \ DatingApp.API”。       使用根名称空间“ DatingApp.API”。       使用项目目录“ D：\ DatingApp \ DatingApp.API \”。       正在查找DbContext类...       查找IDesignTimeDbContextFactory实现...       正在寻找应用服务提供商...       正在寻找IWebHost存取器...       使用环境“发展”。       通过“程序”上的IWebHost访问器使用应用程序服务提供程序。       找到了DbContext'DataContext'。       在项目中查找DbContext类...       使用上下文“ DataContext”。       System.InvalidOperationException：实体类型“值”需要定义一个主键。          在Microsoft.EntityFrameworkCore.Infrastructure.ModelValidator.ValidateNonNullPrimaryKeys（IModel   模型）          在Microsoft.EntityFrameworkCore.Infrastructure.ModelValidator.Validate（IModel   模型）          在Microsoft.EntityFrameworkCore.Infrastructure.RelationalModelValidator.Validate（IModel   模型）          在Microsoft.EntityFrameworkCore.Internal.SqliteModelValidator.Validate（IModel   模型）          在Microsoft.EntityFrameworkCore.Infrastructure.ModelSource.CreateModel（DbContext   上下文，IConventionSetBuilder ConventionSetBuilder，IModelValidator   验证器）          在Microsoft.EntityFrameworkCore.Infrastructure.ModelSource。<> c__DisplayClass5_0.b__1（）          在System.Lazy 1.ViaFactory(LazyThreadSafetyMode mode) at System.Lazy 1.ExecutionAndPublication（LazyHelper执行AndPublication，布尔值useDefaultConstructor）处          在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_1(IServiceProvider p) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor 2.VisitCallSite（IServiceCallSite   callSite，TArgument参数）          在Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped（ScopedCallSite   scopedCallSite，ServiceProviderEngineScope范围）          在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参数）          在Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped（ScopedCallSite   scopedCallSite，ServiceProviderEngineScope范围）          在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 1   访问者）          在Microsoft.EntityFrameworkCore.Infrastructure.AccessorExtensions.GetService [TService]（IInfrastructure 1 accessor) at Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.CreateContext(Func 1   厂）          在Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.CreateContext（String   contextType）          在Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.AddMigration（String   名称，字符串       outputDir，字符串contextType）          在Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigrationImpl（String   名称，字符串outputDir，字符串contextType）          在Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigration。<> c__DisplayClass0_1。<。ctor> b__0（）          在Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase。<> c__DisplayClass3_0`1.b__0（）          在Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute（操作   行动）       实体类型“值”要求定义主键。

0 个答案:

没有答案
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