我首先使用EF6代码来创建我的数据库。昨晚一切都运行良好,现在当我运行update-database命令时,我得到以下异常:
PM> update-database
Specify the '-Verbose' flag to view the SQL statements being applied to the target database.
System.ArgumentNullException: Value cannot be null.
Parameter name: extent
at System.Data.Entity.Utilities.Check.NotNull[T](T value, String parameterName)
at System.Data.Entity.Core.Mapping.StorageEntitySetMapping..ctor(EntitySet extent, StorageEntityContainerMapping entityContainerMapping)
at System.Data.Entity.ModelConfiguration.Edm.DbDatabaseMappingExtensions.AddEntitySetMapping(DbDatabaseMapping databaseMapping, EntitySet entitySet)
at System.Data.Entity.ModelConfiguration.Edm.Services.TableMappingGenerator.Generate(EntityType entityType, DbDatabaseMapping databaseMapping)
at System.Data.Entity.ModelConfiguration.Edm.Services.DatabaseMappingGenerator.GenerateEntityTypes(DbDatabaseMapping databaseMapping)
at System.Data.Entity.ModelConfiguration.Edm.Services.DatabaseMappingGenerator.Generate(EdmModel conceptualModel)
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.Utilities.DbContextExtensions.<>c__DisplayClass1.<GetModel>b__0(XmlWriter w)
at System.Data.Entity.Utilities.DbContextExtensions.GetModel(Action`1 writeXml)
at System.Data.Entity.Utilities.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.UpdateRunner.Run()
at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
at System.AppDomain.DoCallBack(CrossAppDomainDelegate callBackDelegate)
at System.Data.Entity.Migrations.Design.ToolingFacade.Run(BaseRunner runner)
at System.Data.Entity.Migrations.Design.ToolingFacade.Update(String targetMigration, Boolean force)
at System.Data.Entity.Migrations.UpdateDatabaseCommand.<>c__DisplayClass2.<.ctor>b__0()
at System.Data.Entity.Migrations.MigrationsDomainCommand.Execute(Action command)
Value cannot be null.
Parameter name: extent
这是Context Class
public class WheelTrackDb : DbContext
{
public WheelTrackDb(): base("DefaultConnection"){ }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Driver>()
.HasRequired(d => d.Vehicle)
.WithOptional(v => v.Driver)
.Map(m => m.MapKey("VehicleId"));
modelBuilder.Entity<TransactionLog>()
.HasRequired(t => t.Acceptor)
.WithMany()
.HasForeignKey(t => t.AcceptorId)
.WillCascadeOnDelete(false);
modelBuilder.Entity<TransactionLog>()
.HasRequired(t => t.Donor)
.WithMany()
.HasForeignKey(t => t.DonorId)
.WillCascadeOnDelete(false);
modelBuilder.Entity<Violation>()
.HasRequired(v => v.GSMDeviceLog)
.WithMany(g => g.Violations)
.HasForeignKey(v => v.GSMDeviceLogId);
modelBuilder.Entity<RouteFence>().Ignore(r => r.PolygonVertices);
modelBuilder.Entity<Vehicle>()
.HasRequired(v => v.License)
.WithRequiredPrincipal();
modelBuilder.Entity<MessageCounter>()
.HasRequired(m => m.License)
.WithOptional(l => l.MessageCounter)
.Map(m => m.MapKey("LicenseId"));
modelBuilder.Entity<GSMDeviceLog>()
.HasRequired(g => g.Vehicle)
.WithMany(t => t.GsmDeviceLogs);
}
public DbSet<UserInfo> UserInfos{ get; set; }
public DbSet<TransactionLog> TransactionLogs{ get; set; }
public DbSet<Driver> Drivers { get; set; }
public DbSet<Vehicle> Vehicles{ get; set; }
public DbSet<VehicleGroup> VehicleGroups { get; set; }
public DbSet<License> Licenses { get; set; }
public DbSet<Policy> Policys { get; set; }
public DbSet<GSMDeviceLog> GSMDeviceLogs { get; set; }
public DbSet<MessageCounter> MessageCounters { get; set; }
public DbSet<Violation> Violations { get; set; }
public DbSet<OwnershipPaper> OwnershipPapers { get; set; }
public DbSet<Subscriber> Subscribers { get; set; }
}
这是配置:
internal sealed class Configuration : DbMigrationsConfiguration<WheelTrack.Models.WheelTrackDb>
{
public Configuration()
{
AutomaticMigrationsEnabled = true;
}
protected override void Seed(WheelTrack.Models.WheelTrackDb context)
{
}
}
我搜索了互联网,发现我应该只在我的上下文类中拥有属性。我检查了三次,它只有dbset属性。我无法弄清楚发生了什么。任何帮助将不胜感激。感谢。
答案 0 :(得分:29)
发现问题。实际上我在UserInfo模型中有一个HttpPosetedFileBase
属性,EF无法绑定到数据库列。
在其上放置一个未映射的属性使其有效。
[NotMapped]
public HttpPostedFileBase Photo { get; set; }
因此,对于遇到此问题的其他人,请确保两件事:
您的上下文应始终包含DbSets属性。示例 -
public DbSet<Policy> Policies { get; set; }
模型类中不应存在EF无法绑定到数据库列的类型。
希望它有所帮助。