流畅的NHibernate多对多在链接表上创建聚集索引

发布于 2024-09-13 04:15:13 字数 708 浏览 3 评论 0原文

我有两个处于多对多关系的实体。

 public class SecurityGroupMappingOverride : IAutoMappingOverride<SecurityGroup>
{
    public void Override(AutoMapping<SecurityGroup> mapping)
    {
        mapping.HasManyToMany(x => x.Actions).ParentKeyColumn("securityGroupId").ChildKeyColumn("actionId").
            LazyLoad().Table("ActionGroups");

        mapping.HasManyToMany(x => x.Members).ParentKeyColumn("securityGroupId").ChildKeyColumn("userId").
            LazyLoad().Inverse().Table("UserGroups");

        mapping.Map(x => x.Name).Length(64);

    }
}

因此，我想在表 UserGroups 的两列（userId、securityGroupId）上创建聚集索引。

或者只是在这两列上的用户组上创建主键，因为同时不能是两个相同的链接。

谢谢

原文

I have two entities in a many-to-many relationship.

 public class SecurityGroupMappingOverride : IAutoMappingOverride<SecurityGroup>
{
    public void Override(AutoMapping<SecurityGroup> mapping)
    {
        mapping.HasManyToMany(x => x.Actions).ParentKeyColumn("securityGroupId").ChildKeyColumn("actionId").
            LazyLoad().Table("ActionGroups");

        mapping.HasManyToMany(x => x.Members).ParentKeyColumn("securityGroupId").ChildKeyColumn("userId").
            LazyLoad().Inverse().Table("UserGroups");

        mapping.Map(x => x.Name).Length(64);

    }
}

So I want to create an clustered index on both columns (userId, securityGroupId) from table UserGroups.

Or just to create a Primary Key on UserGroups on them both columns, as at same time could not be two same links.

Thanks

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你曾走过我的故事 2024-09-20 04:15:13

我假设您希望 NHibernate 的 SchemaExport 工具为您生成这些索引/键。

对于多对多包（FluentNHibernate 的默认集合类型），SchemaExport 生成：

create UserGroups (
    securityGroupId INT not null,
    userId INT not null,
)

对于多对多集 strong>，它会生成：

create UserGroups (
    securityGroupId INT not null,
    userId INT not null,
    primary key (securityGroupId, userId)
)

...因此只需将 .AsSet() 添加到您的映射中即可。

mapping.HasManyToMany(x => x.Members)
    .AsSet()
    // ... etc.

如果您考虑一下手袋和套装是什么，这确实是有道理的。套装中的元素应该是唯一的，而包则没有唯一性要求。

I assume you're wanting NHibernate's SchemaExport tool to generate these indexes/keys for you.

For many-to-many bags (FluentNHibernate's default collection type), SchemaExport generates:

create UserGroups (
    securityGroupId INT not null,
    userId INT not null,
)

For many-to-many sets, it generates:

create UserGroups (
    securityGroupId INT not null,
    userId INT not null,
    primary key (securityGroupId, userId)
)

... so just add .AsSet() to your mapping.

mapping.HasManyToMany(x => x.Members)
    .AsSet()
    // ... etc.

It makes sense, really, if you think about what bags and sets are. The elements of a set are supposed to be unique, whereas bags don't have a uniqueness requirement.

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