blocks|key|2636183|text|我想答案取决于您的域模型与数据库表有多大的不同。有时，您可能无法单独使用ORM实现DDD持久性。这不应妨碍您或导致您设计您的域模型围绕您的数据库。这也是DDD拥有存储库接口概念的原因，因为扭曲模型的任务可能非常复杂。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2636184|该指南现在并不比第一次编写时更过时。ORMs可能与此准则兼容，也可能不兼容，但这并不意味着使用其他方法无法实现。|2636185|我同意您的评估，大多数DDD模型是一个1:1的镜像数据库。简单的回答是，坚持并不总是容易的，但绝不是不可能的。|2636186|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|H|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|I|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|J|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|G|$]]

I guess the answer depends on just how different your domain models are from your database tables. Sometimes you may not be able to achieve DDD persistence using ORMs alone. This should not deter you or cause you to design your domain models around your database. This is also the very reason DDD has the concept of a repository interface, because the task of peristing your models may be very complex.

The guideline is no more obsolete now than when it was first written. ORMs may or may not be compatible with this guideline, however it doesn't mean it's not achievable using other methods.

I do agree with your assessment that most DDD models are a 1:1 mirror of the database. The short answer is that persistence is not always easy, but never impossible.

blocks|key|291928|text|DDD中的一个关键思想是有界上下文，它包含以下几个内容：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|291929|普适语言|unordered-list-item|291930|骨料根|291931|实体|291932|域服务|291933|域事件|291934|数据库表|291935|DDD有两种可能的情况，取决于天气，项目是绿色的，或者是棕色的。|291936|在使用DDD完成的绿色字段项目中，将有明确的子域、明确的有界上下文，您将拥有被认为在有界上下文中的数据库表，并且您将得到表之间的1:1映射--这是一种使用JPA+/+Hibernate的实体.等。|291937|在现有数据库不可更改的brown字段项目中，一个数据库可以支持多个有界上下文，而且一些表可能在不同的有界上下文中将其列的不同部分映射到不同的域实体。|291938|在Vaughn+Vernon的“实现领域驱动设计”一书中，第66页到第68页对这个问题进行了很好的讨论。|291939|entityMap^0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Z|8|@]|9|@]|A|$]]|$1|E|3|F|5|D|7|10|8|@]|9|@]|A|$]]|$1|G|3|H|5|D|7|11|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|12|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|13|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|14|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|15|8|@]|9|@]|A|$]]|$1|Q|3|R|5|D|7|16|8|@]|9|@]|A|$]]|$1|S|3|T|5|D|7|17|8|@]|9|@]|A|$]]|$1|U|3|V|5|6|7|18|8|@]|9|@]|A|$]]|$1|W|3|-4|5|6|7|19|8|@]|9|@]|A|$]]]|X|$]]

One the key ideas in DDD is bounded context that contains several things such as: 

<ul>
<li>Ubiquitous Language</li>
<li>Aggregate Roots</li>
<li>Entities</li>
<li>Domain Services</li>
<li>Domain Events</li>
<li>Database Tables </li>
</ul>

There are two possible situations that can arise with DDD depending on weather the project is green field or brown filed. 

<ul>
<li>In a green field project with where everything is done with DDD there will be clear sub domains, clear bounded contexts, you will have database tables that are considered to be within the bounded context and you will get 1 : 1 mapping between tables an entities kind of what you with JPA / Hibernate ... etc. </li>
<li>In a brown field project with an existing database that can not be changed one database could support multiple bounded contexts and it is possible that some tables might have different parts of their columns mapped to different domain entities in different bounded contexts. </li>
</ul>

There is a good discussion of this question on page 66 to 68 in the book "Implementing Domain Driven Design" by Vaughn Vernon.

blocks|key|1337358|text|如果您使用Java，您可以使用遵循Data模式的MyBatis来实现这一点。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1337359|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

If you use Java, you can use MyBatis which follows the Data Mapper pattern to achieve that.

blocks|key|1337434|text|实体和表之间的“令人失望的1:1映射”可能在两方面使您失望--无法从多个表填充实体，也无法从同一表填充多个实体。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1337435|似乎您对后者更感兴趣，大多数ORM都可以使用，即使仅通过在ORM的单独映射“实例”中为一个表定义不同的映射也是可能的。描述了实体框架的一种解决方案这里和这里。|offset|length|1337436|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/11197754/entity-framework-one-database-multiple-dbcontexts-is-this-a-bad-idea|1|https://msdn.microsoft.com/en-us/magazine/jj883952.aspx^0|0|21|2|0|24|2|1|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Q|8|@]|9|@$D|R|E|S|1|T]|$D|U|E|V|1|W]]|A|$]]|$1|F|3|-4|5|6|7|X|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|M]]|N|$5|I|J|K|A|$L|O]]]]

The "disappointing [1:1] mapping" between entities and tables might disappoint you in two ways -- not being able to populate an entity from multiple tables, and not being able to populate multiple entities from the same table.

As it seems you're more interested in the latter, it's possible with most ORM's, even if only by defining different mappings for one table in separate mapping "instances" of the ORM. A solution for Entity Framework is described <a href="https://stackoverflow.com/questions/11197754/entity-framework-one-database-multiple-dbcontexts-is-this-a-bad-idea">here</a> and <a href="https://msdn.microsoft.com/en-us/magazine/jj883952.aspx" rel="nofollow noreferrer">here</a>.

In DDD, a guideline states that domain models are not supposed to have something to do with persistence. It means that different domain models may rely on the same tables. Meanwhile, it seems that this goal is pretty difficult to reach, because of technical limitations in ORMs in transforming models (I suppose ?). Is there a way, with actual ORMs, to create very specific domain models that rely on the same tables in database, and to prevent the disappointing [1:1] mapping between entities and tables we have in 99.99% of DDD implementations ? Do these technical limitations (?) make the guideline obsolete ?

Thanks,

DDD, can different domain models rely on the same set of tables

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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在DDD中，一条指南指出域模型不应该与持久化有关。这意味着不同的域模型可能依赖于相同的表。同时，由于ORMs在转换模型方面的技术限制(我想?)，这个目标似乎很难实现。对于实际的ORM，是否有一种方法可以创建非常具体的域模型，这些模型依赖于数据库中相同的表，并防止99.99%的DDD实现中实体和表之间令人失望的1:1映射...

问DDD，不同的域模型是否依赖于同一组表？
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问DDD，不同的域模型是否依赖于同一组表？EN