EF5 Code First（无法从用法中推断出错误）

Question

好的，我一直在拔头发，因为我根本无法建立多对多的关系。我有以下两种型号：

public class UserProfile
{
    [Key]
    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int UserId { get; set; }
    public string UserName { get; set; }
    public string CompanyName { get; set; }
    public string FirstName { get; set; }
    public string Lastname { get; set; }
    public string EmailAddress { get; set; }
    public string PhoneNumber { get; set; }
    public bool? ChangePassword { get; set; }
    public bool? Deletable { get; set; }

    //Add more Properties for more fields

    public virtual IQueryable<CompanyInformation> ParentCompany { get; set; }
}

和

public class CompanyInformation
{
    [Key]
    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int id { get; set; }

    [DisplayName("Company Name:")]
    public string companyName { get; set; }

    [DisplayName("Website Address:")]
    [Url(ErrorMessage="The Website field is not a valid fully-qualified http, https, or ftp URL. (Example: http://www.website.com)")]
    public string website { get; set; }
    public string contactTitle { get; set; }

    [DisplayName("Contact First Name:")]
    public string contactFirstName { get; set; }
    //[Required]
    [DisplayName("Contact Last Name:")]
    public string contactLastName { get; set; }

    [Phone]
    [DisplayName("Phone Number:")]
    public string contactPhoneNumber { get; set; }

    [DisplayName("Address Display?")]
    public bool displayAddress { get; set; }
    [DisplayName("Phone Number?")]
    public bool displayPhoneNumber { get; set; }

    [DisplayName("Address 1:")]
    public string address1 { get; set; } 
    [DisplayName("Address 2:")]
    public string address2 { get; set; }

    [DisplayName("City:")]
    public string city { get; set; }

    [DisplayName("State:")]
    public string state { get; set; }

    [DisplayName("Zip/Postal Code:")]
    public string zipCode { get; set; }

    [DisplayName("Search Engine?")]
    public bool allowSearchEngines { get; set; }


    //Navigation Property
    public virtual IQueryable<UserProfile> CompanyUsers{ get; set; }

}

我试图在这两者之间建立多对多的关系，但我不知道如何正确地做到这一点。我应该提一下，我对 EF Code First 非常陌生。 我的上下文类如下所示：

public class myDB : DbContext
{
    public SchedulerDB()
        : base("DefaultConnection")
    {

    }

    public DbSet<UserProfile> UserProfiles { get; set; }
    public DbSet<CompanyInformation> Companies { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Entity<UserProfile>().HasMany(e => e.ParentCompanies).WithMany(e => e.CompanyUsers);            
    }

}

好的，只要我添加上面的模型构建器，我就会收到以下错误：

The type arguments for method 'System.Data.Entity.ModelConfiguration.EntityTypeConfiguration<Scheduler.Model.UserProfile>.HasMany<TTargetEntity>(System.Linq.Expressions.Expression<System.Func<Scheduler.Model.UserProfile,System.Collections.Generic.ICollection<TTargetEntity>>>)' cannot be inferred from the usage. Try specifying the type arguments explicitly.  C:\Users\Hiva\Documents\Project\ToDo\Infrastructure\myDB.cs

我做错了什么？我似乎找不到任何以不同方式使用模型构建器来实现两个表之间的多对多关系的示例。非常感谢您的帮助。

Answer 1

您应该将 ICollection 用于导航属性：

ICollection<UserProfile> CompanyUsers{ get; set; }

和

ICollection<UserProfile> ParentCompanies{ get; set; }

而不是IQueriable