Nhibernate和实体基类

Question

我正在尝试实现具有overriden equals和GetHashcode的抽象基实体类。。。这是我的实体基类

public abstract class Entity<TId>
{
public virtual TId Id { get; protected set; }
protected virtual int Version { get; set; }
public override bool Equals(object obj)
{
  return Equals(obj as Entity<TId>);
}
private static bool IsTransient(Entity<TId> obj)
{
  return obj != null &&
         Equals(obj.Id, default(TId));
}
private Type GetUnproxiedType()
{
  return GetType();
}
public virtual bool Equals(Entity<TId> other)
{
  if (other == null)
    return false;
  if (ReferenceEquals(this, other))
    return true;
  if (!IsTransient(this) &&
      !IsTransient(other) &&
      Equals(Id, other.Id))
  {
    var otherType = other.GetUnproxiedType();
    var thisType = GetUnproxiedType();
    return thisType.IsAssignableFrom(otherType) ||
           otherType.IsAssignableFrom(thisType);
  }
  return false;
}
public override int GetHashCode()
{
  if (Equals(Id, default(TId)))
    return base.GetHashCode();
  return Id.GetHashCode();
}

}

实体基本Id的值是如何分配的？

我的类的主键有不同的数据类型，而且每个类的名称也不同。这是我的课程示例：

public class Product : Entity
{
    public virtual Guid ProductId { get; set; }
    public virtual string Name { get; set; }
    public virtual string Description { get; set; }
    public virtual Decimal UnitPrice { get; set; }
}
public class Customer : Entity
{
    public virtual int CustomerID { get; set; }
    public virtual string FirstName { get; set; }
    public virtual string LastName { get; set; }
    public virtual int Age { get; set; }
}

我对如何设置基类的ID属性有点困惑。有人能就此向我提出建议吗？我将感谢任何帮助。

Answer 1

您只需要将一个类型传递给继承的基类。

参见实体中的注释：

public class Product : Entity<Guid>
{
    // The ProductId property is no longer needed as the
    // Id property on the base class will be of type Guid
    // and can serve as the Id
    //public virtual Guid ProductId { get; set; }
    public virtual string Name { get; set; }
    public virtual string Description { get; set; }
    public virtual Decimal UnitPrice { get; set; }
}
public class Customer : Entity<int>
{
    // The CustomerID property is no longer needed as the
    // Id property on the base class will be of type int
    // and can serve as the Id
    // public virtual int CustomerID { get; set; }
    public virtual string FirstName { get; set; }
    public virtual string LastName { get; set; }
    public virtual int Age { get; set; }
}

现在，在您的NHibernate映射文件中，只需指定Id属性的数据库列。