Fluent nhibernate 一对多映射
您好,我在使用fluent nhibernate进行映射时遇到问题:Fluent nhibernate 一对多映射,fluent-nhibernate,Fluent Nhibernate,您好,我在使用fluent nhibernate进行映射时遇到问题: public ProductMap() { Id(x => x.ProductID); Map(x => x.ProductName); Map(x => x.QuantityPerUnit); Map(x => x.ReorderLevel); Map(x => x.SupplierID);
public ProductMap()
{
Id(x => x.ProductID);
Map(x => x.ProductName);
Map(x => x.QuantityPerUnit);
Map(x => x.ReorderLevel);
Map(x => x.SupplierID);
Map(x => x.UnitPrice);
Map(x => x.UnitsInStock);
Map(x => x.UnitsOnOrder);
Map(x => x.CategoryID);
Map(x => x.Discontinued);
References(x => x.Category).Column("CategoryID");
References(x => x.Supplier).Column("SupplierID");
Table("dbo.Products");
}
public SupplierMap()
{
Id(x => x.SupplierID);
Map(x => x.Address);
Map(x => x.City);
Map(x => x.CompanyName);
Map(x => x.ContactName);
Map(x => x.ContactTitle);
Map(x => x.Country);
Map(x => x.Fax);
Map(x => x.HomePage);
Map(x => x.Phone);
Map(x => x.PostalCode);
Map(x => x.Region);
HasMany(x => x.Products)
.KeyColumn("SupplierID")
.Inverse()
.Cascade.All();
Table("dbo.Suppliers");
}
public CategoryMap()
{
Id(x => x.CategoryID);
Map(x => x.CategoryName);
Map(x => x.Description);
Map(x => x.Picture);
HasMany(x => x.Products)
.KeyColumn("CategoryID")
.Inverse()
.Cascade.All();
Table("dbo.Categories");
}
当我尝试这样做时:
var sessionFactory = SessionFactory.CreateSessionFactory();
using (var session = sessionFactory.OpenSession())
{
Product fresh = new Product()
{
ProductName = "AddFromNhibernate",
SupplierID = 3,
CategoryID = 5,
QuantityPerUnit = "1kg pcg",
UnitPrice = (decimal) 35,
UnitsInStock = (short?) 15,
UnitsOnOrder = 0,
ReorderLevel = null,
Discontinued = true
};
using (session.BeginTransaction())
{
session.Save(fresh);
session.Transaction.Commit();
}
}
我得到了系统索引。
我的映射有什么问题?当我尝试获取一些数据时,工作正常,但添加失败。我尝试在ProductMap中引用specyfie Propertyreference,但没有任何帮助。我注意到您将一些列映射了两次 以
ProductMap
为例:
public ProductMap()
{
(...)
Map(x => x.SupplierID);
(...)
Map(x => x.CategoryID);
References(x => x.Category).Column("CategoryID");
References(x => x.Supplier).Column("SupplierID");
(...)
}
在这种情况下,如果希望保留原始ID和引用(因为它们映射到数据库表中的同一列),则应绕过其中一个中的插入/更新
我的意思是:
public ProductMap()
{
(...)
Map(x => x.SupplierID).Not.Insert().Not.Update();
(...)
Map(x => x.CategoryID).Not.Insert().Not.Update();
References(x => x.Category).Column("CategoryID");
References(x => x.Supplier).Column("SupplierID");
(...)
}
如果不这样做,当NHibernate开始设置插入/更新参数时,您可能会得到您描述的
异常。thx,它现在可以工作了。但我有一个问题:当我这样做的时候,我必须为产品创建类别和供应商对象,不能简单地根据代码设置它们的id。有没有可能是双向的?我设置了CategoryId和SupplierID还是设置了CategoryId和SupplierID?我想你的疑问适合另一个帖子(问题):)