实体框架 Fluent API 不考虑基类属性

EF 6.1 :

我们刚刚启动了一个有很多继承的项目。选定的继承数据库映射类型是每个层次结构的表。问题是，当尝试使用 add-migration 生成迁移时，会引发以下错误：

The foreign key component 'VersionId' is not a declared property on type 'SER'. Verify that it has not been explicitly excluded from the model and that it is a valid primitive property.

以下是使用的类和配置类：

public class Version : BaseObject
{
    public virtual ICollection<SER> ListOfSER { get; set; }
}

public abstract class AbsractR : BaseObject
{
    public int ParentId { get; set; }
    public int ChildId { get; set; }

    public int VersionId { get; set; }
    public virtual Version Version { get; set; }
}

public class SER : AbstractR
{
    public int SEDId
    {
        get
        {
            return base.ChildId;
        }
        set
        {
            base.ChildId = value;
        }
    }
    public virtual SED SED { get; set; }
}

public abstract class AbstractD : BaseObject
{
}

public class SED : AbstractD
{
    public virtual ICollection<SER> ListOfSER { get; set; }
}


public class SDContext : BaseContext
{
    public DbSet<Version> Versions { get; set; }
    public DbSet<AbstractD> Ds { get; set; }
    public DbSet<AbstractR> Rs { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.Configurations.Add(new VersionConfiguration());

        #region Refs
        modelBuilder.Configurations.Add(new AbstractRConfiguration());
        modelBuilder.Configurations.Add(new SERConfiguration());
        #endregion

        #region Defs
        modelBuilder.Configurations.Add(new AbstractDConfiguration());
        modelBuilder.Configurations.Add(new SEDConfiguration());
        #endregion
    }
}

public class BaseObjectConfiguration<T> : EntityTypeConfiguration<T> where T : BaseObject
{
    public BaseObjectConfiguration()
    {
        #region Key
        this.HasKey(bo => bo.Id);
        #endregion

        #region Properties
        this.Property(bo => bo.Id).IsRequired();
        this.Property(bo => bo.IsDeleted).IsRequired();
        this.Property(bo => bo.LastModificationDate).IsOptional();
        this.Property(bo => bo.OptimisticVersion).IsConcurrencyToken().IsRequired().IsRowVersion();
        this.Property(bo => bo.CreationDate).IsRequired();
        this.Property(bo => bo.DeletionDate).IsOptional();
        #endregion
    }
}

public class VersionConfiguration : BaseObjectConfiguration<Version>
{
    public VersionConfiguration() : base()
    {
        #region Properties
        #endregion

        #region Objects
        this.HasMany(mdv => mdv.ListOfSER).WithRequired().HasForeignKey(ser => ser.VersionId).WillCascadeOnDelete(false);
        #endregion

        #region Table
        this.ToTable("Versions");
        #endregion
    }
}

public class AbstractRConfiguration : BaseObjectConfiguration<AbstractR>
{
    public AbstractRConfiguration()
        : base()
    {
        #region Properties
        this.Property(ser => ser.VersionId).IsRequired();
        #endregion

        #region Objects
        this.HasRequired(ar => ar.Version).WithMany().HasForeignKey(ar => ar.VersionId).WillCascadeOnDelete(false);
        #endregion

        #region Table
        this.ToTable("Refs");
        #endregion
    }
}

public class SERConfiguration : BaseObjectConfiguration<SER>
{
    public SERConfiguration()
        : base()
    {
        #region Properties
        this.Ignore(ser => ser.SEDId);
        #endregion

        #region Objects
        this.HasRequired(ser => ser.SED).WithMany(sed => sed.ListOfSER).HasForeignKey(ser => ser.ChildId).WillCascadeOnDelete(false);
        #endregion

        #region Table
        this.ToTable("Refs");
        #endregion
    }
}

public class AbstractDConfiguration : BaseObjectConfiguration<AbstractD>
{
    public AbstractDConfiguration() : base()
    {
        this.ToTable("Defs");
    }
}

public class SEDConfiguration : BaseObjectConfiguration<SED>
{
    public SEDConfiguration()
        : base()
    {
        #region Properties
        #endregion

        #region Objects
        this.HasMany(sed => sed.ListOfSER).WithRequired(sed => sed.SED).HasForeignKey(sed => sed.ChildId).WillCascadeOnDelete(false);
        #endregion

        #region Table
        this.ToTable("Defs");
        #endregion
    }
}

我知道我们可以使用 [ForeignKey] 属性来告诉派生类上的导航属性应该使用父抽象类中定义的列。我们希望避免使用 DataAnnotations。我只是不明白为什么它会抛出这个错误。 “版本”导航属性是在 AbstractR 配置中定义的，而不是在 SER 配置中定义的（这也应该有效，因为 SER 继承自 AbstractR），对吗？

其次，当删除 Version 属性和映射时，SER 映射中使用的“ChildId”和“ParentId”属性也会出现相同的问题。这是一个已知问题吗？难道我做错了什么 ？

PS：为简单起见，已删除 ParentId 映射，因为它似乎与 ChildId 映射存在相同的问题。

有谁知道为什么会发生这种问题？

UPDATE

经过更多研究后，Fluent API 似乎无法使用基类属性进行映射。是对的吗 ？这是一种想要的行为吗？为什么 DataAnnotations 能够使用基类属性而不是 Fluent API ？不是所有基类属性都插入到每个类中，还是使用某种装饰器模式读取？

只要主体也使用基类类型的导航属性，您就可以使用基类属性作为外键关联。

校长 (Version）已声明ListOfSER作为类型的导航属性SER作为受抚养人

public class Version : BaseObject
{
    public virtual ICollection<SER> ListOfSER { get; set; }
}

，但配置使用基类属性（VersionId) 作为外键关联

public class VersionConfiguration : BaseObjectConfiguration<Version>
{
    public VersionConfiguration()
        : base()
    {
        HasMany(mdv => mdv.ListOfSER)
            .WithRequired()
            .HasForeignKey(ser => ser.VersionId) // -> belongs to base class
            .WillCascadeOnDelete(false);
    }
}

配置时不允许的ForeignKeyConstraintConfiguration，看一下代码摘录

foreach (var dependentProperty in dependentPropertyInfos)
{
    var property
        = dependentEnd.GetEntityType() // -> SER
            .GetDeclaredPrimitiveProperty(dependentProperty); // -> VersionId

    if (property == null) // VersionId is not part of SER metamodel
    {
        throw Error.ForeignKeyPropertyNotFound(
            dependentProperty.Name, dependentEnd.GetEntityType().Name);
    }

    dependentProperties.Add(property);
}

解决方案1将改变ListOfSER输入来自SER into AbstractR.

public class Version : BaseObject
{
    public virtual ICollection<AbstractR> ListOfSER { get; set; }
}

这会更有意义，VersionId是在基类上定义的，任何派生类型都应该能够使用这个外键关联，对吧？但不幸的是Version类型仅允许SER与 相关联Version.

定义 Fluent api 配置时也会出现不一致的情况。

public class VersionConfiguration : BaseObjectConfiguration<Version>
{
    public VersionConfiguration()
        : base()
    {
        HasMany(mdv => mdv.ListOfSER)
            .WithRequired() // -> this should be WithRequired(x => x.Version)
            .HasForeignKey(ser => ser.VersionId)
            .WillCascadeOnDelete(false);
    }
}
public class AbstractRConfiguration : BaseObjectConfiguration<AbstractR>
{
    public AbstractRConfiguration()
        : base()
    {
        HasRequired(ar => ar.Version)
            .WithMany() // -> this should be WithMany(x => x.ListOfSER)
            .HasForeignKey(ar => ar.VersionId)
            .WillCascadeOnDelete(false);
    }
}

更重要的是，您不必在两侧进行配置。只需将其放在VersionConfiguration or AbstractRConfiguration就足够了。

解决方案2将移动Version and VersionId从基类到SER， 如果你想Version只与SER.

public class Version : BaseObject
{
    public virtual ICollection<SER> ListOfSER { get; set; }
}
public abstract class AbstractR : BaseObject
{
}
public class SER : AbstractR
{
    public int VersionId { get; set; }
    public virtual Version Version { get; set; }
}

并配置Version配置或SER配置。

public class VersionConfiguration : BaseObjectConfiguration<Version>
{
    public VersionConfiguration()
        : base()
    {
        HasMany(mdv => mdv.ListOfSER)
            .WithRequired(x => x.Version)
            .HasForeignKey(ser => ser.VersionId)
            .WillCascadeOnDelete(false);
    }
}
public class SERConfiguration : BaseObjectConfiguration<SER>
{
    public SERConfiguration()
        : base()
    {
        HasRequired(ar => ar.Version)
            .WithMany(x => x.ListOfSER)
            .HasForeignKey(ar => ar.VersionId)
            .WillCascadeOnDelete(false);
    }
}