Question

你好我使用流利的nhibernate我的映射有问题：

     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");
    }

当我尝试做的时候：

    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();
            }
        }

我收到了System.IndexOutOfRangeException。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。我想在ProductMap中专门针对参考物业参考，但它没有帮助。

Answer 1

我注意到你两次映射了一些列。

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，如果要保留原始ID 和引用（因为它们映射到数据库表中的同一列），您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");
    (...)
}

如果你没有这样做，你可能会得到NHibernate开始设置插入/更新参数时所描述的Exception。

流畅的NHibernate映射一对多

1 个答案: