1
我正在使用mvc4 asp.net web應用程序。我想添加一個遷移，但顯示一個錯誤，我不知道如何解決它。 這裏的類代碼：實體框架添加遷移錯誤：「值不能爲空」
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Web;
namespace POCOs
{
public class Consultant
{
public int Id { get; set; }
public string Nom { get; set; }
public string Prenom { get; set; }
public string RefCommercial { get; set; }
public string DateNaissance { get; set; }
public int CIN { get; set; }
public string Fonction { get; set; }
public string Tel { get; set; }
public string Experience { get; set; }
public string Email { get; set; }
public HttpPostedFileBase CV { get; set; }
public ICollection<Prestation> prestations { get; set; }
public Consultant()
{
prestations = new HashSet<Prestation>();
}
}
}
和這裏的時候，我想補充一個遷移是我得到的錯誤：
Add-Migration
cmdlet Add-Migration at command pipeline position 1
Supply values for the following parameters:
Name: cv
System.ArgumentNullException: Value cannot be null.
Parameter name: key
at System.Collections.Generic.Dictionary`2.FindEntry(TKey key)
at System.Collections.Generic.Dictionary`2.TryGetValue(TKey key, TValue& value)
at System.Data.Entity.ModelConfiguration.Configuration.Mapping.SortedEntityTypeIndex.Add(EdmEntitySet entitySet, EdmEntityType entityType)
at System.Data.Entity.ModelConfiguration.Configuration.Mapping.EntityMappingService.Analyze()
at System.Data.Entity.ModelConfiguration.Configuration.ModelConfiguration.ConfigureEntityTypes(DbDatabaseMapping databaseMapping, DbProviderManifest providerManifest)
at System.Data.Entity.ModelConfiguration.Configuration.ModelConfiguration.Configure(DbDatabaseMapping databaseMapping, DbProviderManifest providerManifest)
at System.Data.Entity.DbModelBuilder.Build(DbProviderManifest providerManifest, DbProviderInfo providerInfo)
at System.Data.Entity.DbModelBuilder.Build(DbConnection providerConnection)
at System.Data.Entity.Internal.LazyInternalContext.CreateModel(LazyInternalContext internalContext)
at System.Data.Entity.Internal.RetryLazy`2.GetValue(TInput input)
at System.Data.Entity.Internal.LazyInternalContext.InitializeContext()
at System.Data.Entity.Internal.LazyInternalContext.get_CodeFirstModel()
at System.Data.Entity.Infrastructure.EdmxWriter.WriteEdmx(DbContext context, XmlWriter writer)
at System.Data.Entity.Migrations.Extensions.DbContextExtensions.<>c__DisplayClass1.<GetModel>b__0(XmlWriter w)
at System.Data.Entity.Migrations.Extensions.DbContextExtensions.GetModel(Action`1 writeXml)
at System.Data.Entity.Migrations.Extensions.DbContextExtensions.GetModel(DbContext context)
at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration, DbContext usersContext)
at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration)
at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.GetMigrator()
at System.Data.Entity.Migrations.Design.ToolingFacade.GetPendingMigrationsRunner.RunCore()
at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.Run()
Value cannot be null.
Parameter name: key
任何幫助嗎？
您的HttpPostedFileBase屬性可能是問題 - EF將映射到哪個數據類型？您可以使用[NotMapped]數據註解來排除它：[http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.schema.notmappedattribute%28v=vs.110%29.aspx]（ http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.schema.notmappedattribute%28v=vs.110%29.aspx） – markpsmith
爲了澄清，這實際上是一個實體框架問題。 ASP.NET MVC純粹是一種Web技術; ASP.NET項目默認包含Entity Framework來處理數據庫訪問。我已經相應地編輯了標籤。 – anaximander