应该使用枚举作为歧视者吗？ [英] Should I ever use Enums as discriminators?
问题描述
为了支持现有系统中的新功能，我正在考虑实施在我的数据库模式中，对于一个实体表的某种形式的歧视。
要开始做最少的工作，我首先决定一个整数列，为了可读性，在业务实体层的C＃枚举。这将提供可能最终成长为实际多态性的穷人的多态性，也许可能导致策略模式。
我决定咨询博客圈，因为我从来没有使用枚举完全舒服 - 我想知道，我应该跳过枚举并直接进行结构体或类吗？
首先我发现一个断言，一个href =http://devpinoy.org/blogs/cruizer/archive/2007/09/12/enums-are-evil.aspx =nofollow noreferrer>枚举是邪恶的'，但我觉得这是一个过度泛化，并不直接解决我的用例。
如果我做一个枚举，那么有一个很好的讨论，我可以如何href =https://stackoverflow.com/questions/1008090/c-enum-values>通过在我的枚举中添加额外的元数据来扩展我的里程数。
接下来，我遇到了Jimmy Bogard对枚举类，并在 NHibernate中的策略和歧视者'
我应该跳过枚举并直接进行枚举类？或者有任何人有任何其他建议，如何添加一个简单的实体鉴别器到我的域模型。
更新：
我还会补充说，NHibernate和LINQ to SQL（以及所有其他ORM相关的数据访问方法）都可以使用枚举非常诱人，因为它们让您在映射中透明地映射一个歧视列。
映射枚举类是否容易？
相关问题：
免责声明：
尽管我粗心地使用术语实体（小写为'e'）我不会在这里声称正在讨论DDD ...
这些枚举类看起来很整洁，我经常嫉妒地看着Java的枚举。
我认为通常的规则适用：做最简单的事情可能会工作。如果您发现自己在枚举上有多个开关，那么这是一种气味，有时间考虑您发现的模式。
否则，为什么你不需要你自己的东西？
When do Enumerations break down?
To support a new feature in an existing system, I was just considering implementing some form of discriminator to an entity table in my database schema.
In wanting to begin by doing the least thing that will work I first of all decided on an integer column and a C# enum at the business entity layer for the sake of readability. This would provide the poor-man's polymorphism that may eventually grow into an actual polymorphism and perhaps towards a Strategy pattern.
I decided to consult the blogosphere as I've never been entirely comfortable with using enums - I wondered, should I skip the enum and go straight for a struct or a class?:
First of all I found an assertion that 'Enums are Evil', but I felt this was an over-generalization which does not directly address my use-case.
If I do go for an enum then there's a good discussion of how I can extend my mileage by adding extra metadata to my enum.
Next, I came across Jimmy Bogard's discussions of Enumeration Classes and further discussed in 'Strategies and discriminators in NHibernate'
Should I skip the enums and go straight for Enumeration Classes? Or does anyone have any other suggestions for how to add a simple entity discriminator to my domain model.
Update:
I'd also add that both NHibernate and LINQ to SQL (and probably all other ORM-related data-access methods) make the use of enums very enticing as they let you map a discriminator column transparently in the mapping.
Would it be as easy to map an Enumeration Class?
Related questions:
Disclaimer:
Despite my careless use of the term entity (with a lower case 'e') I don't claim to be discussing DDD here...
Those Enumeration Classes look neat, I've often looked jealously at Java's enums.
I think the usual rules apply: do the Simplest Thing That Could Possibly Work. If you find yourself with more than one switch on the enum, then that's a smell, and time to consider the pattern you've found.
Otherwise, why burden yourself with something you don't need?
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