流畅的 NHibernate +多个数据库

发布于 2024-08-28 19:53:59 字数 531 浏览 6 评论 0原文

我的项目需要处理三个数据库，这意味着三个会话工厂。问题是，如果我用流畅的 nhibernate 做这样的事情：

.Mappings(m => m.FluentMappings.AddFromAssembly(Assembly.GetExecutingAssembly()))

工厂将拾取所有映射，甚至是对应于另一个数据库的映射，

我已经看到，当使用自动映射时，你可以做这样的事情，并按名称空间过滤：

.Mappings(m => m.AutoMappings.Add(
    AutoMap
       .AssemblyOf<Product>()
       .Where(t => t.Namespace == "Storefront.Entities")))

我还没有找到类似的流畅映射，有可能吗？我能想到的唯一解决方案是：要么为每个数据库映射类创建单独的程序集，要么将每个实体显式添加到工厂配置中。

如果可能的话，我宁愿避免两者。谢谢。

原文

My project needs to handle three databases, that means three session factories. The thing is if i do something like this with fluent nhibernate:

.Mappings(m => m.FluentMappings.AddFromAssembly(Assembly.GetExecutingAssembly()))

the factories would pick up all the mappings, even the ones that correspond to another database

I've seen that when using automapping you can do something like this, and filter by namespace:

.Mappings(m => m.AutoMappings.Add(
    AutoMap
       .AssemblyOf<Product>()
       .Where(t => t.Namespace == "Storefront.Entities")))

I havent found anything like this for fluent mappings, is it possible?? The only solutions I can think of are: either create separate assemblies for each db mapping classes or explicitly adding each of the entities to the factory configuration.

I would prefer to avoid both, if possible. Thanks.

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

葬花如无物 2024-09-04 19:53:59

我已经使用 Fluent 映射文件上的（我自己的）属性来指示实体所属的数据库来实现这一点。我还有“默认”数据库的概念，并且假设没有属性的映射文件驻留在其中在默认数据库中（它可能会减少您需要装饰的类的数量）。
然后，我有初始化代码，它为每个数据库创建一个会话工厂，并为每个数据库使用反射来查找所有 ClassMap 类，检查属性以确定它属于哪个数据库，并相应地注册每个 ClassMap。

映射文件示例：

  [FluentNHibernateDatabase("MySecurityDatabase")]
  public class SystemUserMap : ClassMap<SystemUser>
  {
    public SystemUserMap()
    {
      Id(x => x.SystemUserId);
      Map(x => x.LoginId);
      Map(x => x.LoginPassword);
      Map(x => x.UserFirstName);
      Map(x => x.UserSurname);
      References(x => x.UserOrganisation, "OrganisationId");
    }
  }

显然我已经定义了引用/使用的数据库列表。
到目前为止，我的实现是有效的，但我遇到了障碍（我希望有人可以帮忙）：

我在这里问了我的问题：
如何识别特定实体的会话工厂使用 Fluent NHibernate 和多个数据库

I've implemented exactly this using (my own) Attribute on the Fluent mapping file to dictate which DB the entity belongs in. I've also got a concept of a 'default' database, and mapping files without an attribute are assumed to reside in the default DB (it may cut down on the number of classes you need to decorate).
I then have initialisation code which creates a Session Factory per database, and for each, uses reflection to find all ClassMap classes,examines the attribute to determine which DB it belongs to, and registers each ClassMap accordingly.

A mapping file example:

  [FluentNHibernateDatabase("MySecurityDatabase")]
  public class SystemUserMap : ClassMap<SystemUser>
  {
    public SystemUserMap()
    {
      Id(x => x.SystemUserId);
      Map(x => x.LoginId);
      Map(x => x.LoginPassword);
      Map(x => x.UserFirstName);
      Map(x => x.UserSurname);
      References(x => x.UserOrganisation, "OrganisationId");
    }
  }

Obviously I've defined a list of the DBs that are referenced/used.
My implementation works so far as I've taken it, but I've hit a snag (that I hope someone can help out with):

I've asked my question here:
How to identify a particular entity's Session Factory with Fluent NHibernate and Multiple Databases

回复收藏 0 原文

相守太难 2024-09-04 19:53:59

执行此操作的简单方法是将数据库名称放入架构中

public sealed class CustomerMapping: ClassMap<Customer>
{
    public CustomerMapping()
    {
        Schema("Northwind.dbo");
        Table("Customer");
    }
}

public sealed class Customer2Mapping: ClassMap<Customer2>
{
    public CustomerMapping()
    {
        Schema("Northwind2.dbo");
        Table("Customer");
    }
}

然后，假设所有表都可以通过同一连接字符串访问，则您只需要一个会话工厂

The easy way of doing this is to put the database name into the Schema

public sealed class CustomerMapping: ClassMap<Customer>
{
    public CustomerMapping()
    {
        Schema("Northwind.dbo");
        Table("Customer");
    }
}

public sealed class Customer2Mapping: ClassMap<Customer2>
{
    public CustomerMapping()
    {
        Schema("Northwind2.dbo");
        Table("Customer");
    }
}

Then, provided all tables are accessible on the same connection string, you only need one session factory

回复收藏 0 原文

巴黎盛开的樱花 2024-09-04 19:53:59

您还可以按类型进行过滤。这是来自“绿色字段”AutoPersistenceModel 的一行注释代码，我在与“棕色字段一”（即两个数据库）相同的程序集中使用。但我只需要过滤一种类型，因此我没有费心去拆分遗留程序集。如果每个数据库有很多它们，那么在我看来，按程序集分割它们可能是最好的选择。

如果 FNH 能够提供某种内置的多数据库支持，那就太酷了，但我不知道如何真正做到这一点；也许是某种 SessionFactories 字典，但每种情况都是如此独特。

HTH，
贝里尔

    /// <summary>
    /// This would simply call <see cref="AutoMapHelpers.GetAutoMappingFilter"/> but we need to 
    /// exclude <see cref="LegacyProject"/> also for now.
    /// </summary>
    private static bool _getIncludedTypesFilter(Type t) {
        return _isNotLegacy(t) && AutoMapHelpers.GetAutoMappingFilter(t);
    }
    private static bool _isNotLegacy(Type t) { return !t.Equals(typeof(LegacyProject)); }

You can also filter by types. Here's a line of commented code from a "green field" AutoPersistenceModel I use in the same assembly as a "brown field one" (ie, two databases). But there is only one type I need to filter on, so I haven't bothered to split out a legacy assembly. If you have got lots of them per db then splitting them by assemblies is probably going to be best IMO.

It would be cool if FNH could provide some sort of built in multi-db support but I don't know how that really could be done; some sort of dictionary of SessionFactories maybe but every situation is just so unique.

HTH,
Berryl

    /// <summary>
    /// This would simply call <see cref="AutoMapHelpers.GetAutoMappingFilter"/> but we need to 
    /// exclude <see cref="LegacyProject"/> also for now.
    /// </summary>
    private static bool _getIncludedTypesFilter(Type t) {
        return _isNotLegacy(t) && AutoMapHelpers.GetAutoMappingFilter(t);
    }
    private static bool _isNotLegacy(Type t) { return !t.Equals(typeof(LegacyProject)); }

回复收藏 0 原文