流利的NHibernate：如何在多对多连接表上创建聚集索引？

问题描述

为了在SQL Azure上使用我的Fluent NHibernate映射，我需要在每个表上都有一个聚集索引。 Fluent NHibernate为多对多连接创建的默认堆表显然不会这样做，因为它们没有主键。

我希望能够告诉关系的一方为它的连接表创建一个聚集索引，但我不知道如何。这里是我的映射看起来像：

$ p $ public class UserMap：ClassMap< User> {
public UserMap（）
{
表（用户）;
Id（x => x.UserId）.GeneratedBy.Identity（）。Column（UserId）;
Map（x => x.UserName）.Unique（）。Not.Nullable（）。Length（DataConstants.UserNameLength）.Column（UserName）;
Map（x => x.Email）.Unique（）。Not.Nullable（）。Length（DataConstants.EmailAddressLength）.Column（Email）;
Map（x => x.Password）.Not.Nullable（）。Length（DataConstants.PasswordHashLength）.Column（Password）;
HasMany（x => x.Clicks）.Cascade.AllDeleteOrphan（）;
HasManyToMany（x => x.Roles）.Cascade.SaveUpdate（）。Table（UsersInRole）。ParentKeyColumn（UserId）。
ChildKeyColumn（RoleId）;





如果你需要，请告诉我更多信息！


解决方案

我不知道Fluent是否直接支持它（如果没有，只需包含xml）您可以使用

 < nhibernate-mapping> 
< database-object> 
< create>在UsersInRole（UserId，RoleId）上创建聚集索引ix< / create> 
< drop> drop index UsersInRole.ix< / drop> 
< / database-object> 
< / nhibernate-mapping> 
  




In order to use my Fluent NHibernate mappings on SQL Azure, I need to have a clustered index on every table. The default heap tables that Fluent NHibernate creates for many-to-many joins obviously don't do this as they don't have primary keys.

I want to be able to tell one side of the relationship to create a clustered index for its join table, but I'm not sure how. Here's what my mappings look like:

 public class UserMap : ClassMap<User>{
    public UserMap()
    {
        Table("Users");
        Id(x => x.UserId).GeneratedBy.Identity().Column("UserId");
        Map(x => x.UserName).Unique().Not.Nullable().Length(DataConstants.UserNameLength).Column("UserName");
        Map(x => x.Email).Unique().Not.Nullable().Length(DataConstants.EmailAddressLength).Column("Email");
        Map(x => x.Password).Not.Nullable().Length(DataConstants.PasswordHashLength).Column("Password");
        HasMany(x => x.Clicks).Cascade.AllDeleteOrphan();
        HasManyToMany(x => x.Roles).Cascade.SaveUpdate().Table("UsersInRole").ParentKeyColumn("UserId").
            ChildKeyColumn("RoleId");

    }
}

Please let me know if you need any more information!

解决方案

I don't know if Fluent supports it directly (if not, just include the xml), but you can do it with Auxiliary Database Objects

<nhibernate-mapping>
  <database-object>
    <create>create clustered index ix on UsersInRole(UserId, RoleId)</create>
    <drop>drop index UsersInRole.ix</drop>
  </database-object>
</nhibernate-mapping>

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