实体类型< type>不是当前上下文模型的一部分 [英] The entity type <type> is not part of the model for the current context

问题描述

我正在进入实体框架，但我不确定我是否缺少代码优先方法中的关键点。

我正在使用通用存储库基于 https://genericunitofworkandrepositories.codeplex.com/ 的代码，并创建了我的实体。 p>

但是当我尝试访问或修改实体时，我遇到以下情况：

System.InvalidOperationException：实体类型Estate不是当前上下文模型的
的一部分。

我试图从我的存储库访问它：

  public virtual void Insert（TEntity entity）
 {
（（IObjectState）实体）.ObjectState = ObjectState.Added; 
 _dbSet.Attach（entity）; //<  - 这里出现错误
 _context.SyncObjectState（entity）; 
} 
  

数据库（./SQLEXPRESS）创建的很好，但实体表）在启动时不会创建。

我想知道我是否需要显式设置实体的映射？ EF自己不能这样做吗？

我的实体是：

  public class Estate：EntityBase 
 {
 public int EstateId {get;组; } 
 public string Name {get;组; 
} 
  

我的上下文是这样的：

  public partial class DimensionWebDbContext：DbContextBase // DbContextBase inherits DbContext 
 {
 public DimensionWebDbContext（）：
 base（DimensionWebContext） 
 {
 Database.SetInitializer&DimensionWebDbContext>（new CreateDatabaseIfNotExists&DimensionWebDbContext>（））; 
 Configuration.ProxyCreationEnabled = false; 
} 
 
 public new IDbSet< T>设置< T>（）其中T：class 
 {
 return base.Set< T>（）; 
} 
 
} 
  

有什么具体原因发生错误？我尝试启用迁移并启用自动迁移，无需任何帮助。

解决方案

将其放在您的自定义 DbContext class：

  protected override void OnModelCreating（DbModelBuilder modelBuilder）
 {
 modelBuilder.Entity< Estate>（）。ToTable（Estate）; 
} 
  

如果您的表在启动时未创建，这就是为什么。您需要在OnModelCreating方法覆盖中告诉DbContext关于它们。

您可以在此处执行自定义的每个实体映射，也可以将它们分离为单独的 EntityTypeConfiguration< T> 类。

I am getting into the Entity Framework, but I am unsure if I am missing a critical point in the code-first approach.

I am using a generic repository pattern based on the code from https://genericunitofworkandrepositories.codeplex.com/ and have created my entities.

But when I try to access or modify the entity I run into the following:

System.InvalidOperationException: The entity type Estate is not part of the model for the current context.

It happens when I am trying to access it from my repository:

public virtual void Insert(TEntity entity)
{
    ((IObjectState)entity).ObjectState = ObjectState.Added;
    _dbSet.Attach(entity); // <-- The error occurs here
    _context.SyncObjectState(entity);
}

The database (./SQLEXPRESS) is created just fine, but the entities (tables) is just not created on startup.

I am wondering if I need to explicit set the mapping of the entities? Is EF not able to this by its own?

My Entity is:

public class Estate : EntityBase
{
    public int EstateId { get; set; }
    public string Name { get; set; }
} 

My context is as so:

public partial class DimensionWebDbContext : DbContextBase // DbContextBase inherits DbContext
{
    public DimensionWebDbContext() :
        base("DimensionWebContext")
    {
        Database.SetInitializer<DimensionWebDbContext>(new CreateDatabaseIfNotExists<DimensionWebDbContext>());
        Configuration.ProxyCreationEnabled = false;
    }

    public new IDbSet<T> Set<T>() where T : class
    {
        return base.Set<T>();
    }

}

Is there any specific reason why this error occurs? I have tried enable migrations and enable automatic migrations without any help either.

解决方案

Put this in your custom DbContext class:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<Estate>().ToTable("Estate");
}

If your tables are not created on startup, this is why. You need to tell the DbContext about them in the OnModelCreating method override.

You can either do custom per-entity mappings here, or separate them out into separate EntityTypeConfiguration<T> classes.

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