NHibernate左外部加入子类

Question

我有2个实体产品和图像。并非所有图像都是产品图像，图像是文件的子类，下面是我的实体。我需要找到所有与产品无关的图像。我是新来的实体检索，并尝试了许多方法。任何想法或链接将不胜感激。

public class File 
    { 
     #region Feilds 
     public virtual int Id { get; set; } 
     public virtual string Name { get; set; } 
     public virtual Enumerations.File.FileType Type { get; set; } 
     public virtual string Extension { get; set; } 
     public virtual string Path { get; set; } 
     public virtual DateTime DateCreated { get; set; } 
     public virtual DateTime DateModified { get; set; } 
     #endregion 
    } 

public class Image : File 
{ 
    #region Fields 
    public virtual string ImageName { get; set; } 
    public virtual string Description { get; set; } 
    public virtual bool Active { get; set; } 
    public virtual DateTime DateTaken { get; set; } 
    #endregion 
} 

public class Product 
{ 
    #region Properties 
    public virtual int Id { get; set; } 
    public virtual string Name { get; set; } 
    public virtual string Description { get; set; } 
    public virtual decimal Price { get; set; } 
    public virtual decimal Weight { get; set; } 
    public virtual bool IsDigital { get; set; } 
    public virtual DateTime DateCreated { get; set; } 
    public virtual IList<Category> ProductCategories { get; set; } 
    public virtual IList<ProductAttribute> ProductAttributes { get; set; } 
    public virtual IList<Image> ProductImages { get; set; } 
    #endregion 
} 

Answer 1

您可以使用Critiria不存在子查询......

IList<Image> images = session.CreateCriteria<Image>("img") 
     .Add(Expression.Not(Subqueries.Exists(DetachedCriteria.For<ProductImageLink>("pil") 
        .SetProjection(Projections.Constant(1)) 
        .Add(Expression.EqProperty("img.image_id", "pil.image_id"))))) 
     .List<Image>(); 

哪里ProductImageLink是关联表。

应导致查询像...

select ... from image img where not exists(select 1 from productimagelink pil where img.image_id = pil.image_id);