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我使用EF4瓦特/代碼優先CTP特徵產生一個簡單的複合構圖實體模型:關係映射代碼僅CTP(使用繼承何時?)
public abstract partial class CacheEntity
{
[Key]public string Hash { get; set; }
public string Creator { get; set; }
public int EntityType { get; set; }
public string Name { get; set; }
public string Predecessor { get; set; }
public DateTime DateTimeCreated { get; set; }
public virtual ICollection<CacheReference> References { get; set; }
}
public partial class CacheBlob : CacheEntity
{
public byte[] Content { get; set; }
}
public partial class CacheCollection : CacheEntity
{
public virtual ICollection<CacheEntity> Children { get; set; }
}
public class CacheReference
{
public string Hash { get; set; }
[Key]public string Reference { get; set; }
public virtual CacheEntity Entity { get; set; }
}
public class CacheEntities : DbContext
{
public DbSet<CacheEntity> Entities { get; set; }
public DbSet<CacheReference> References { get; set; }
}
在我拆出原始/集的派生類它的所有工作很好,但現在我得到這樣的:
Unable to determine the principal end of the 'Cache.DataAccess.CacheEntity_References'
relationship. Multiple added entities may have the same primary key.
我想,它可能已被越來越糊塗,所以我想我會拼出來明確地使用了流暢的界面,而不是DataAnnotation屬性。下面是我覺得正確定義的關係:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<CacheEntity>().HasKey(ce => ce.Hash);
modelBuilder.Entity<CacheEntity>().HasOptional(ce => ce.References).WithMany();
modelBuilder.Entity<CacheReference>().HasKey(ce => ce.Reference);
modelBuilder.Entity<CacheReference>().HasRequired(cr => cr.Entity).WithOptional();
}
但我一定是錯誤的,因爲現在我得到這樣的:使用流利的API產生不同的錯誤
Entities in 'CacheEntities.CacheReferenceSet' participate in the
'CacheReference_Entity' relationship. 0 related 'Entity' were found. 1 'Entity' is expected.
各種方式,但沒有成功,所以我開始懷疑,當我使用繼承時,這些是否需要以不同的方式完成。
任何線索,鏈接,想法,指導將非常受歡迎。