c# – 如何在ASP.NET MVC中组织DAL

我正在尝试在asp.net mvc项目中组织数据访问层.我已经阅读了很多不同的文章,所以我仍然有一些问题要完成这个问题：

>我应该为数据库中的每个实体创建存储库实例,还是为所有或一个基本实例创建存储库实例,例如PostRepository可以包含Post,Comment和Tag等实体？
>在控制器中,我必须获取一些数据,转换为ViewModel并将其传递到视图中.这是最好的去处？服务,控制器或其他什么？
>如果是服务.我应该创建多少服务？对于每个实体,如果是必要的话,还会转入Controller 3或4服务？或者也许就像我想在存储库中这样做？ (创建一个包含一些存储库计数的公共服务.PostService,带有PostRepository,CommentRepository和TagRepository等存储库)

解决方法:

这是我的看法：

Should I create instances of repository for every entity in database
or for all or one genereal instance, for example PostRepository can
include entities like Post, Comment and Tag?

拥有一个通用的存储库可以为您节省大量的维护工作.您可以实现单个通用存储库,如：

/// <summary>
/// This interface provides an abstraction for accessing a data source.
/// </summary>
public interface IDataContext : IDisposable
{
    IQueryable<T> Query<T>() where T : class;

    T Add<T>(T item) where T : class;

    int Update<T>(T item) where T : class;

    void Delete<T>(T item) where T : class;

    /// <summary>
    /// Allow repositories to control when SaveChanges() is called
    /// </summary>
    int SaveChanges();
}

并在单个上下文类中实现上面的接口.

有些人也实现了单独的特定存储库.

In controller I have to get some data, transform in into ViewModel and
pass it into view. Where is the best place to do this? Services,
Controller or something else?

在可从DA,服务和Web访问的单独程序集中定义所有模型(DTO或实体或POCO)类.服务方法返回模型实例,控制器将它们转换为viewmodel(使用AutoMapper)并传递给视图.同样在post方法控制器中,首先将VM转换为Model,然后传递给Service层以进行持久性或处理.

If it is Service. How many services should I create? Also for every
entity and pass into Controller 3 or 4 services if it is necessery? Or
maybe do it like I wanted to do it in repository? (Create one common
service which would contain some count of repositories. PostService,
with repositories like PostRepository, CommentRepository and
TagRepository)

我强烈建议您定义非常具体的服务.使用单一责任原则来定义您的服务.每项服务都应提供相关的功能集.例如. AuthService将验证用户不向其发送电子邮件,即EmailService作业.

我建议的模式与不同的服务非常合作.例如：

public class DriverSearchService : IDriverSearchService
{
    private readonly IBlobService _blobService;
    private readonly IDataContext _dataContext;

    public DriverSearchService(IDataContext dataContext, IBlobService blobService)
     {
         _blobService = blobService;
        _dataContext = dataContext;
     }

    public void SaveDriveSearch(int searchId)
    {
        // Fetch values from temp store and clear temp store
        var item = context.Query<SearchTempStore>().Single(s => s.SearchId == searchId);

        // Temp object is latest so update the main store
        var mainSearch = context.Query<Search>().Single(s => s.Id == searchId);
        mainSearch.LastExecutedOn = DateTime.UtcNow;
        mainSearch.DataAsBlob = item.DataAsBlob;
        context.Update(mainSearch);
    }
}

标签：c,asp-net-mvc,data-access-layer
来源： https://codeday.me/bug/20190624/1275659.html