c# - ASP.NET Core, EF Core 同时一对一和一对多

Question

我目前正在使用 ASP.NET 核心。我有一个 BaseModel 和 SubModel，其结构如下:

class BaseClass{
   SubClass MainSubClass {get;set;}
   List<SubClass> SubClasses {get;set;} 
}

当我尝试用它添加迁移时，我得到这个错误:

Unable to determine the relationship represented by navigation property 'StoreModel.StoreMainPhoto' of type 'StorePhotoModel'. Either manually configure the relationship, or ignore this property from the model.`*

真正的数据模型是...

在StoreModel.cs

[Table("Stores")]
public class StoreModel
{

    [Key]
    public int Id { get; set; }

    [Required]
    [MaxLength(25)]
    public string StoreName { get; set; }

    [MaxLength(80)]
    public string StoreShortDescription { get; set; }

    [MaxLength(4000)]
    public string StoreFullDescription { get; set; }

    public string StoreLocation { get; set; }
    public string StoreAddress { get; set; }


    #region graphics Data
    public StorePhotoModel StoreMainPhoto { get; set; }
    public ICollection<StorePhotoModel> StorePhotos { get; set; }
    #endregion

    public ICollection<MenuModel> Menus { get; set; }
    public ICollection<StoreReviewModel> StoreReviews { get; set; }

    #region store contacts
    public string StorePhoneNumber { get; set; }
    public string StoreExtraContacts { get; set; }
    #endregion

    public StoreModel()
    {
        StorePhotos = new Collection<StorePhotoModel>();
        Menus = new Collection<MenuModel>();
        StoreReviews = new Collection<StoreReviewModel>();
    }
}

在StorePhotoModel.cs

[Table("StorePhotos")]
public class StorePhotoModel : MediaModel
{

    // base Store
    public int BaseStoreId { get; set; }
    [ForeignKey(nameof(BaseStoreId))]
    public StoreModel BaseStore { get; set; }
}

Answer 1

Entity Framework 对这两个模型之间的关系感到困惑。

在 StoreModel 中你有这个:

public StorePhotoModel StoreMainPhoto { get; set; } //one to one
public ICollection<StorePhotoModel> StorePhotos { get; set; } //one to many

这表明 StoreModel 与 StorePhotoModel 具有一对一和一对多关系。

你没有在问题中指出应该是什么关系，所以我无法评论哪个是正确的。

更新

试试这个:

[Table("Stores")]
public class StoreModel
{

    [Key]
    public int Id { get; set; }

    [Required]
    [MaxLength(25)]
    public string StoreName { get; set; }

    [MaxLength(80)]
    public string StoreShortDescription { get; set; }

    [MaxLength(4000)]
    public string StoreFullDescription { get; set; }

    public string StoreLocation { get; set; }
    public string StoreAddress { get; set; }

    public int StoreMainPhotoId {get;set;}


    #region graphics Data
    [ForeignKey(nameof(StoreMainPhotoId))]
    public StorePhotoModel StoreMainPhoto { get; set; }
    public ICollection<StorePhotoModel> StorePhotos { get; set; }
    #endregion

    public ICollection<MenuModel> Menus { get; set; }
    public ICollection<StoreReviewModel> StoreReviews { get; set; }

    #region store contacts
    public string StorePhoneNumber { get; set; }
    public string StoreExtraContacts { get; set; }
    #endregion

    public StoreModel()
    {
        StorePhotos = new Collection<StorePhotoModel>();
        Menus = new Collection<MenuModel>();
        StoreReviews = new Collection<StoreReviewModel>();
    }
}

更新2

您可以将 OnModelCreating 重写为这样的内容。

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<StoreModel>()
        .HasMany(x => x.StorePhotos)

    modelBuilder.Entity<StoreModel>()
        .HasRequired(x => x.StoreMainPhoto)
        .HasForeignKey(x => x.StoreMainPhotoId)
}

请注意这是未经测试的，因此您可能需要进行调整。您可以在这里找到与您的问题类似的问题:

• Both One-To-One and One-To-Many relationships in Entity Framework 5 Code First

• Entity Framework Code First: How can I create a One-to-Many AND a One-to-One relationship between two tables?

• Entity Framework Code First: How can I create a One-to-Many AND a One-to-One relationship between two tables?