存储库模式和/或/ vs业务逻辑层 [英] Repository pattern and/or/vs business logic layer

问题描述

我有一个问题我想知道你的意见。

我正在尝试使用Repository Pattern。我有一个存储库对象将数据加载到POCO。我还创建了一个业务逻辑层，它增加了一些功能，但基本上包装了POCO。所以最终我有一个BLL，它加载了使用存储库的DAO。

我对这个解决方案不太满意。我有三层，但我觉得BLL没有提供足够的功能来保留它。另一方面，我不想将我的逻辑放在存储库层和数据访问层？

所以我的问题是我应该在哪里应用逻辑？你使用哪个解决方案（DAO + repo或DAO + BLL + rep或任何其他）？

解决方案

在设计域时，有两种基本的方法来考虑业务规则。

1。）域实体是基本的POCO / DTO 秒。你把它们交给域名服务。这些服务可能与另一个类一样简单，或者他们真的可以是另一个服务器上的实际服务器。

  var user = repository .Find（x => x.UserName == userName）; 
 if（userLogonService.IsValidUser（user，password））{
 userLogonService.UpdateUserAsLoggedOn（user）; 
} 
 repository.SaveChanges（）; 
  

2。）域实体包含自己的操作逻辑。这更接近许多MVC模式。因为你问，这是我喜欢的模型。

  var user = repository.Find （x => x.UserName == userName）; 
 if（user.CheckPassword（password））{
 user.LogOnNow（）; 
} 
 repository.SaveChanges（）; 
  

两者都是完全有效的模式。 ＃1具有独立的业务运营层，但遭受贫血域模型。 ＃2可以导致大域实体，如果您的域名开始变得复杂，或者模型可以做很多事情。

编辑＃1：回应John Kraft

Oven.Bake（myPizza）与myPizza.Bake（）

我大部分同意。你有单独的烤箱服务，还是有几十个可用的烤箱存放在烘箱里，烤箱只是另一个域实体？在＃2中，烤箱是域的一部分。我倾向于做域名建模的方式，大多数名词都是域实体，除非你确定是完全一个。

但是比萨饼烘烤时会发生什么。

 界面ICanBeBaked {
 int BakeMinutes {get; } 
 int BakeTemp {get; } 
 void Bake（）; 
} 
 class Pizza：ICanBeBaked {
 int BakeMinutes {get {return 15; }} 
 int BakeTemp {get {return 425; }} 
 void Bake（）{
 //熔化奶酪！ 
 this.isBaked = true; 
} 
} 
 class Oven {
 void Bake（ICanBeBaked thingToBake）{
 //设置temp，保留这个烤箱的持续时间等
 thingToBake.Bake（）; 
} 
} 
  

I have a problem I want to know your opinion.

I am trying to use Repository Pattern. I have a repository object which load data to a POCO. I have also created a Business logic layer which adds a little bit of functionality but basically wraps the POCO. So in the end I have a BLL which loads DAO with usage of repository.

I am not very happy with this solution. I have a three layers but I feel that BLL is not providing enought functionality to keep it there. On the other hand I do not want to put my logic in the repository layer nor data access layer?

So my question is where should I put logic for application? Which solution do you use(DAO + repo or DAO + BLL + rep or any other)?

解决方案

There are two basic ways to think about business rules when designing your domain.

1.) The domain entities are basic POCO/DTOs. And you hand them off to domain services. These services could be as simple as another class, or they really could be actual services sitting on another server.

var user = repository.Find(x => x.UserName == userName);
if (userLogonService.IsValidUser(user, password)) {
   userLogonService.UpdateUserAsLoggedOn(user);
}
repository.SaveChanges();

2.) The domain entities contain their own operation logic. This is closer to what many MVC patterns will follow. And since you asked, this is the model that I prefer.

var user = repository.Find(x => x.UserName == userName);
if (user.CheckPassword(password)) {
    user.LogOnNow();
}
repository.SaveChanges();

Both are completely valid patterns. #1 has a discrete business operation tier, but suffers from an Anemic Domain Model. #2 can lead to big domain entities if you domain starts to become complicated, or if a model can do a lot of things.

EDIT #1: Response to John Kraft

Oven.Bake(myPizza) vs. myPizza.Bake()

I mostly agree. Do you have a single Oven service, or do you have dozens of available ovens stored in an oven repository where oven is just another domain entity? In #2, the oven is part of the domain. The way I tend to do domain modeling, most nouns are domain entities, unless you are 100% sure that there is exactly one of the thing.

But something does happen to pizza when it is baked.

interface ICanBeBaked {
    int BakeMinutes { get; }
    int BakeTemp { get; }
    void Bake();
}
class Pizza : ICanBeBaked {
    int BakeMinutes { get { return 15; } }
    int BakeTemp { get { return 425; } }
    void Bake() {
        // melt cheese!
        this.isBaked = true;
    }
}
class Oven {
    void Bake(ICanBeBaked thingToBake) {
        // set the temp, reserve this oven for the duration, etc.
        thingToBake.Bake();
    }
}

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