流利NHibernate强制外键参考不可空 [英] Fluent NHibernate enforce Not Nullable on Foreign Key Reference
问题描述
基本上试图在一对多的关系的多方面执行非空。
看起来，使用自动映射，它总是使数据库中的父属性Id为空。
我在StackOverFlow上做了一些搜索，发现了类似的问题，但没有任何关于AutoMapping和惯例，但（除非我错过了）。
快速示例...
<$ p $ （）;} {this.Jobs = new List< Job>（）; }
public virtual Guid Id {get;组; }
public virtual string Name {get;组; }
公共虚拟IList<作业>工作{get;保护组}
}
public class Job //有许多作业
{
public virtual Guid Id {get;组; }
public virtual string Name {get;组; }
//试图使这个字段在数据库中不可空。
public virtual Group Group {get;组; }
}
我以为我可以创建一个像.. 。
public class OneToManyConvention：IHasOneConvention
{
public void Apply（IOneToOneInstance instance）
{
// Nullable（）不是一个有效的方法...
instance.Not.Nullable（）;
$ b但是看起来IOneToOnInstance没有Nullable ） 方法。我可以做到这一点，如果我创建一个地图文件作业，但试图避免任何地图文件，并坚持自动映射。
我碰到这个 Fluent group list链接描述类似的内容。
其中描述了这样的内容...
public class NotNullPropertyConvention：IPropertyConvention
{
public bool Accept（IProperty target）
{
return true;
}
public void Apply（IProperty target）
{
target.Not.Nullable（）;
$ b 但是这提出了...
1）我将如何确定IProperty是一个工作（或任何儿童财产是一个链接回到父母）
2）它提到了这一点页面使用这将覆盖我的手动覆盖，例如。如果一个非常具体的属性链接需要为NULL。这将是一个问题（如果它仍然是一个问题，但不能没有考虑＃1首先考虑）
任何想法呢？我只是错过了什么？
更新1
还是不行。即使以下内容仍然不会在数据库模式中执行Not-Nullable ...
public class FluentConvention：IPropertyConvention
{
public void Apply（IPropertyInstance instance）
{
instance.Not.Nullable（）;
$ / code $ / pre
$ b $ p 它可以用于所有其他字段。 。
/ shrug
有什么想法？
更新2
虽然这不是我正在寻找的答案，但我找到了一个解决方法...
我使用的是NHibernate Validator程序集，在程序集中有一个[NotNull]属性。如果我使用Validator属性来修饰我的类，并在架构创建之前将ValidationEngine关联到NHibernate，那么它会将FK数据库列标记为Not-Nullable（不可空）。
public class Job //有很多作业
{
public virtual Guid Id {get;组; }
public virtual string Name {get;组; }
[NHibernate.Validator.Constraints.NotNull]
public virtual Group Group {get;组;如果有人需要完整的代码来进行NHibernate + ValidationEngine初始化，那么让我们来让我们来看看如何使用NHibernate + ValidationEngine我知道。
仍然在寻找一种方法来使用纯映射约定路由，尽管如果任何人有任何信息...
谢谢！
解决方案您可以在Fluenttly.Configure（）中覆盖自动映射属性作为AutoMap的一部分。
所以你可以这样做：
.Override< Job> （map => map.References（x => x.Group）.Not.Nullable（））
如果你有很多需要这个的类，这不是很方便。
编辑：
您也可以在实现IAutoMappingOverride的类中指定重写，如下所示：
public class JobMappingOverride：IAutoMappingOverride< Job>
{
public void Override（AutoMapping< Job> mapping）
{
mapping.References（x => x.Group）.Not.Nullable（）;
$ / code $ / pre
并包含它：
pre $ .UseOverridesFromAssemblyOf< JobMappingOverride>（）
这样可以让你的流畅配置更清洁一些。
Just getting my feet wet with some Fluent NHibernate AutoMap conventions, and ran into something I couldn't figure out. I assume I'm just not looking in the right place...
Basically trying to enforce NOT-NULL on the "many" side of the one to many relationship.
It seems, using the automapping, it always makes the parent property Id nullable in the database.
I did some searching on StackOverFlow and found similar questions, but nothing relating to AutoMapping and Conventions though (unless I missed it).
Quick example...
public class Group // One Group
{
public Group() { this.Jobs = new List<Job>(); }
public virtual Guid Id { get; set; }
public virtual string Name { get; set; }
public virtual IList<Job> Jobs { get; protected set; }
}
public class Job // Has many Jobs
{
public virtual Guid Id { get; set; }
public virtual string Name { get; set; }
// Trying to make this field not-nullable in the database.
public virtual Group Group { get; set; }
}
I thought I'd be able to just create a convention like...
public class OneToManyConvention : IHasOneConvention
{
public void Apply(IOneToOneInstance instance)
{
// Nullable() isn't a valid method...
instance.Not.Nullable();
}
}
But it seems IOneToOnInstance doesn't have a Nullable() method. I can do this if I create a Map file for Job, but trying to avoid any Map files and stick with auto-mapping.
I came across this link on the Fluent group list describing something similar.
Which describes something like this...
public class NotNullPropertyConvention : IPropertyConvention
{
public bool Accept(IProperty target)
{
return true;
}
public void Apply(IProperty target)
{
target.Not.Nullable();
}
}
But that raises the questions of...
1) How would I determine IProperty to be a Job (or any child property that is a link back to the parent)
2) It made a mention on that page that using this would override my manual overrides, eg. if a very specific property link needed to be NULL. Which would be an issue (if it's still an issue, but can't test without figuring out #1 first)
Any ideas on this? Am I just missing something?
Update 1
Still no go. Even the following still doesn't enforce Not-Nullable in the database schema...
public class FluentConvention : IPropertyConvention
{
public void Apply(IPropertyInstance instance)
{
instance.Not.Nullable();
}
}
It does for all of the other fields though...
/shrug
Any ideas?
Update 2
While this isn't the answer I was looking for, I did find a work around...
I was using NHibernate Validator assembly, and within that assembly there is a [NotNull] attribute. If I decorated my class with the Validator attribute, and associated the ValidationEngine to NHibernate before the schema creation, it would tag the FK database column as Not-Nullable.
public class Job // Has many Jobs
{
public virtual Guid Id { get; set; }
public virtual string Name { get; set; }
[NHibernate.Validator.Constraints.NotNull]
public virtual Group Group { get; set; }
}
If anyone needs the full code for the NHibernate + ValidationEngine initialization, just let me know.
Still looking for a way to do it using the pure mapping convention route though if anyone has any info...
Thanks!
解决方案 You can override the auto-mapped properties as part of your AutoMap in Fluenttly.Configure().
So you can do this:
.Override<Job>(map => map.References(x => x.Group).Not.Nullable())
It's not exactly convenient if you have a lot of classes that need this though.
Edit:
You can also specify the override in a class that implements IAutoMappingOverride like so:
public class JobMappingOverride : IAutoMappingOverride<Job>
{
public void Override(AutoMapping<Job> mapping)
{
mapping.References(x => x.Group).Not.Nullable();
}
}
and include it like so:
.UseOverridesFromAssemblyOf<JobMappingOverride>()
This would keep your fluent configuration a little cleaner.
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