在 SqlServer 提供程序清单中找不到存储类型“Varchar(100)”

Question

我正在开发一个 MVC 4 项目，该项目使用 EF 6 进行与数据库 (SQL Server) 之间的所有操作。我必须进行一些重构才能使用更明确的 Fluent API。基本上，现在项目中的每个实体都有其对应的所有映射的 Fluent API 代码。

当我尝试从包管理器控制台运行 EF 命令时，问题就出现了。这是我收到的错误： 在 SqlServer 提供程序清单中找不到存储类型“Varchar(100)”

这是错误的完整日志：

PM> enable-migrations
Checking if the context targets an existing database...
System.InvalidOperationException: The store type 'Varchar(100)' could not be found in the SqlServer provider manifest
   at System.Data.Entity.Utilities.DbProviderManifestExtensions.GetStoreTypeFromName(DbProviderManifest providerManifest, String name)
   at System.Data.Entity.ModelConfiguration.Configuration.Properties.Primitive.PrimitivePropertyConfiguration.ConfigureColumn(EdmProperty column, EntityType table, DbProviderManifest providerManifest)
   at System.Data.Entity.ModelConfiguration.Configuration.Properties.Primitive.PrimitivePropertyConfiguration.<>c__DisplayClass47_0.<Configure>b__0(Tuple`2 pm)
   at System.Data.Entity.Utilities.IEnumerableExtensions.Each[T](IEnumerable`1 ts, Action`1 action)
   at System.Data.Entity.ModelConfiguration.Configuration.Types.StructuralTypeConfiguration.ConfigurePropertyMappings(IList`1 propertyMappings, DbProviderManifest providerManifest, Boolean allowOverride)
   at System.Data.Entity.ModelConfiguration.Configuration.Types.EntityTypeConfiguration.ConfigurePropertyMappings(DbDatabaseMapping databaseMapping, EntityType entityType, DbProviderManifest providerManifest, Boolean allowOverride)
   at System.Data.Entity.ModelConfiguration.Configuration.Types.EntityTypeConfiguration.Configure(EntityType entityType, DbDatabaseMapping databaseMapping, DbProviderManifest providerManifest)
   at System.Data.Entity.ModelConfiguration.Configuration.ModelConfiguration.ConfigureEntityTypes(DbDatabaseMapping databaseMapping, ICollection`1 entitySets, 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_ModelBeingInitialized()
   at System.Data.Entity.Infrastructure.EdmxWriter.WriteEdmx(DbContext context, XmlWriter writer)
   at System.Data.Entity.Utilities.DbContextExtensions.GetModel(Action`1 writeXml)
   at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration, DbContext usersContext, DatabaseExistenceState existenceState, Boolean calledByCreateDatabase)
   at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration)
   at System.Data.Entity.Migrations.Design.MigrationScaffolder..ctor(DbMigrationsConfiguration migrationsConfiguration)
   at System.Data.Entity.Infrastructure.Design.Executor.CreateMigrationScaffolder(DbMigrationsConfiguration configuration)
   at System.Data.Entity.Infrastructure.Design.Executor.ScaffoldInitialCreateInternal(DbConnectionInfo connectionInfo, String contextTypeName, String contextAssemblyName, String migrationsNamespace, Boolean auto, String migrationsDir)
   at System.Data.Entity.Infrastructure.Design.Executor.ScaffoldInitialCreate.<>c__DisplayClass0_0.<.ctor>b__0()
   at System.Data.Entity.Infrastructure.Design.Executor.OperationBase.<>c__DisplayClass4_0`1.<Execute>b__0()
   at System.Data.Entity.Infrastructure.Design.Executor.OperationBase.Execute(Action action)

我一直在阅读很多博客/帖子如何解决这个问题，但它们似乎都不起作用。这些是我尝试过的一些事情：

1. 重新安装 EntityFramework.dll 和 EntityFrameWork.SqlServer.dll
2. 添加一个虚拟方法来显式加载程序集。这是链接
3. 最初我使用的是 EF 6.3.0 并升级到 EF 6.4.0。我认为升级是问题，所以我降级但仍然有同样的问题。

更新 这是实体的代码：

public class EntityA: BaseEntity
    {
        /// <summary>
        /// Gets or sets Contact identifier
        /// </summary>
        public int Id { get; set; }

        public string Name { get; set; }

        public string Description { get; set; }

        public bool IsActive { get; set; }
}

在单独的类中使用 Fluent API 配置：

public class EntityAConfiguration : EntityTypeConfiguration<EntityA>
    {
        public EntityAConfiguration()
        {
            this.ToTable("EntityA")
                .HasKey(c => c.Id);

            this.Property(c => c.Id)
                .HasColumnName("Id")
                .HasColumnType("int")
                .IsRequired();

            this.Property(c => c.Name)
                .HasColumnName("Name")
                .HasColumnType("Varchar(40)")
                .IsRequired();

            this.Property(c => c.Description)
                .HasColumnName("Description")
                .HasColumnType("Varchar(100)")
                .IsRequired();

            this.Property(c => c.IsActive)
                .HasColumnName("IsActive")
                .HasColumnType("bit");
        }
    }

BaseEntity类只有两个属性：CreatedDate、UpdatedDate。我在需要存储该信息的所有实体中使用该类。

在这一点上，我没有想法如何解决这个问题。如果有人遇到类似的问题，如果您能提供帮助或向我指出任何可能有帮助的信息，我将不胜感激。

Answer 1

这是我收到的错误：在 SqlServer 提供程序清单中找不到存储类型“Varchar(100)”

这是因为它是无效的，正如我上面的评论中提到的，您不能在HasColumnType. 要解决此问题，请参见下文。

public EntityAConfiguration()
        {
            this.ToTable("EntityA")
                .HasKey(c => c.Id);

            this.Property(c => c.Id)
                .HasColumnName("Id")
                .HasColumnType("INT")
                .IsRequired();

            this.Property(c => c.Name)
                .HasColumnName("Name")
                .HasColumnType("VARCHAR")
                .HasMaxLength(40)
                .IsRequired();

            this.Property(c => c.Description)
                .HasColumnName("Description")
                .HasColumnType("VARCHAR")
                .HasMaxLength(100)
                .IsRequired();

            this.Property(c => c.IsActive)
                .HasColumnName("IsActive")
                .HasColumnType("bit");
        }

您现在将看到一个名为 的新属性HasMaxLength，这是您定义长度的地方。这HasColumnType只是类型定义，仅此而已。