Question

这已经在其他多个问题中得到了解决，但是，我已经尝试了那里发布的所有解决方案都没有成功。我正在使用Code-First EF开发ASP.NET MVC应用程序。我正在尝试利用内置的脚手架，以便它可以根据我的Model和DbContext自动为我创建一个Controller。但是，当我尝试以这种方式创建Controller时，我收到以下错误：

'Unable to retrieve metadata for Employer.' Using the same DbCompiledModel to create contexts against different types of database servers is not supported. Instead, create a separate DbCompiledModel for each type of server being used.

我的模型，雇主，我的DbContext，MyDataContext和我的web.config文件的代码如下：

//Employer.cs
public class Employer : Organization, IEmployer
{
    public virtual PhysicalAddress Address { get; set; }

    public virtual ICollection<ContactMethod> ContactMethods { get; set; }

    public int FederalTaxID { get; set; }

    public virtual Client Client { get; set; }
}

-

//MyDataContext.cs
[DbConfigurationType(typeof(MySqlEFConfiguration))]
public class MyDataContext : IdentityDbContext<ApplicationUser>
{
    public MyDataContext()
        : base("DataConnection")
    {

    }

    static MyDataContext()
    {
        Database.SetInitializer(new DataInitializer());
    }

    public DbSet<Client> Clients { get; set; }
    public DbSet<Organization> Organizations { get; set; }      // Store Employer and OrgEntity

    /// <summary>
    /// Sets up unclear relationships between entities before the models are constructued in a database. 
    /// For example, models which extend other models must have their Ids mapped (because it is an 
    /// inherited member, and so is not found by Entity Framework by default)
    /// </summary>
    /// <param name="modelBuilder">the object responsible for constructing the database from code-first</param>
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        //set up parent organization relationship
        modelBuilder.Entity<Organization>()
            .HasOptional(n => n.ParentOrganization)
            .WithMany(o => o.ChildOrganizations)
            .Map(m => m.MapKey("ParentOrganization_Id"));

        //set up the organization-employee assignment
        modelBuilder.Entity<Employee>()
            .HasOptional(a => a.OrganizationAssignment)
            .WithMany(a => a.Employees);

        //used to integrate Identity stuff into same db as Clients, etc.
        modelBuilder.Entity<IdentityUserLogin>().HasKey<string>(l => l.UserId);
        modelBuilder.Entity<IdentityRole>().HasKey<string>(r => r.Id);
        modelBuilder.Entity<IdentityUserRole>().HasKey(r => new { r.RoleId, r.UserId });
    }
}

-

<!--web.config-->
.
.
.
<connectionStrings>
<add name="DataConnection"
     providerName="Mysql.Data.MysqlClient"
     connectionString="server=localhost;user id=myid;password=mypass;persistsecurityinfo=True;database=app_db"/>
</connectionStrings>
.
.
.

来自 this one ， this one 和 this one 等其他帖子。我尝试过很多不同的东西让它发挥作用。这包括注释掉MyDbContext的构造函数，将连接字符串的providerName属性更改为"System.Data.SqlClient"，将连接字符串名称更改为"DefaultConnection"，删除我的连接字符串完全，以及所有这些事情的组合。我确保在尝试添加Controller之间重建。但是，在执行这些不同的更改后，当我尝试添加新的Controller时，仍然会收到相同的错误。

一般来说，我可以找到已经回答的所有问题，但答案对我来说似乎并不合适。我认为将我的案例与链接的案例区分开来的是我的DbContext实际上是IdentityDbContext的一个实例。我相信IdentityDbContext的构造函数只是调用它的基础构造函数，所以我不知道这可能是一个多大的问题。

非常感谢任何帮助。谢谢！

Answer 1

您没有将您的雇主实体映射到模型。这就是编译器无法为Employer检索元数据的原因。首先，如下所示添加DbSet，如果有效，请告诉我。

public DbSet<Client> Clients { get; set; }
public DbSet<Organization> Organizations { get; set; }
public DbSet<Employer> Employers { get; set; }

无法添加控制器（带脚手架）ASP.NET MVC

1 个答案: