如何在 MVC 控制器中实现数据访问层
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【中文标题】如何在 MVC 控制器中实现数据访问层【英文标题】：How to implement a data access layer within MVC Controller 【发布时间】：2017-10-19 14:30:48 【问题描述】：我了解数据访问层或简称 DAL 用于访问和检索数据库中的信息，但我不确定如何在控制器中调用 DAL 数据。 例如，我在我的 DAL 中创建了这个静态类，但我不确定如何将它调用到我的控制器，任何帮助或指南将不胜感激。 DohvatiMetodu 是类的名称。
public static FormInputViewModel DohvatiMetodu()
var viewModel = new FormInputViewModel();
var metoda = new List<Metoda>();
var metodaList = new List<SelectListItem>();
using (var db = new ApplicationDbContext())
metoda = db.Metoda.ToList();
foreach (var metod in metoda)
metodaList.Add(new SelectListItem() Value = metod.Id.ToString(), Text = metod.Naziv);
viewModel.KoristenaMetoda = metodaList;
return viewModel;
【问题讨论】：
DAL 是单独的类文件，用于对数据库执行 CRUD 操作。您可以直接从控制器调用StaticClass.MethodName()。从控制器访问 DAL 没有任何限制，也不会破坏 MVC 中的任何规则。
如果它是一个静态方法，你只需通过ClassName.MethodName 访问它，假设你在范围内有正确的命名空间。当然，现在更常见的是不将事物设为静态，而是使用依赖注入将类放入您的控制器中。
感谢您提供的信息，但我对依赖注入形式的外观很感兴趣？
检查下面的答案
嘎啊啊啊啊啊啊啊啊啊。不要写静态的。这使得模拟/单元测试变得非常困难。
【参考方案1】：
根据用户的许多要求，我使用简单的 CRUD 方法逐步更新了具有完整 存储库模式 的代码：
存储库模式在应用程序的数据层和域层之间添加了一个分离层。它还使应用程序的数据访问部分具有更好的可测试性。
数据库工厂 (IDatabaseFactory.cs)：
public interface IDatabaseFactory : IDisposable
Database_DBEntities Get();
数据库工厂实现（DatabaseFactory.cs）：
public class DatabaseFactory : Disposable, IDatabaseFactory
private Database_DBEntities dataContext;
public Database_DBEntities Get()
return dataContext ?? (dataContext = new Database_DBEntities());
protected override void DisposeCore()
if (dataContext != null)
dataContext.Dispose();
基础接口 (IRepository.cs)：
public interface IRepository<T> where T : class
void Add(T entity);
void Update(T entity);
void Detach(T entity);
void Delete(T entity);
T GetById(long Id);
T GetById(string Id);
T Get(Expression<Func<T, bool>> where);
IEnumerable<T> GetAll();
IEnumerable<T> GetMany(Expression<Func<T, bool>> where);
void Commit();
抽象类（Repository.cs）：
public abstract class Repository<T> : IRepository<T> where T : class
private Database_DBEntities dataContext;
private readonly IDbSet<T> dbset;
protected Repository(IDatabaseFactory databaseFactory)
DatabaseFactory = databaseFactory;
dbset = DataContext.Set<T>();
/// <summary>
/// Property for the databasefactory instance
/// </summary>
protected IDatabaseFactory DatabaseFactory
get;
private set;
/// <summary>
/// Property for the datacontext instance
/// </summary>
protected Database_DBEntities DataContext
get return dataContext ?? (dataContext = DatabaseFactory.Get());
/// <summary>
/// For adding entity
/// </summary>
/// <param name="entity"></param>
public virtual void Add(T entity)
try
dbset.Add(entity);
// dbset.Attach(entity);
dataContext.Entry(entity).State = EntityState.Added;
int iresult = dataContext.SaveChanges();
catch (UpdateException ex)
catch (DbUpdateException ex) //DbContext
catch (Exception ex)
throw ex;
/// <summary>
/// For updating entity
/// </summary>
/// <param name="entity"></param>
public virtual void Update(T entity)
try
// dbset.Attach(entity);
dbset.Add(entity);
dataContext.Entry(entity).State = EntityState.Modified;
int iresult = dataContext.SaveChanges();
catch (UpdateException ex)
throw new ApplicationException(Database_ResourceFile.DuplicateMessage, ex);
catch (DbUpdateException ex) //DbContext
throw new ApplicationException(Database_ResourceFile.DuplicateMessage, ex);
catch (Exception ex)
throw ex;
/// <summary>
/// for deleting entity with class
/// </summary>
/// <param name="entity"></param>
public virtual void Delete(T entity)
dbset.Remove(entity);
int iresult = dataContext.SaveChanges();
//To commit save changes
public void Commit()
//still needs modification accordingly
DataContext.SaveChanges();
/// <summary>
/// Fetches values as per the int64 id value
/// </summary>
/// <param name="id"></param>
/// <returns></returns>
public virtual T GetById(long id)
return dbset.Find(id);
/// <summary>
/// Fetches values as per the string id input
/// </summary>
/// <param name="id"></param>
/// <returns></returns>
public virtual T GetById(string id)
return dbset.Find(id);
/// <summary>
/// fetches all the records
/// </summary>
/// <returns></returns>
public virtual IEnumerable<T> GetAll()
return dbset.AsNoTracking().ToList();
/// <summary>
/// Fetches records as per the predicate condition
/// </summary>
/// <param name="where"></param>
/// <returns></returns>
public virtual IEnumerable<T> GetMany(Expression<Func<T, bool>> where)
return dbset.Where(where).ToList();
/// <summary>
///
/// </summary>
/// <param name="entity"></param>
public void Detach(T entity)
dataContext.Entry(entity).State = EntityState.Detached;
/// <summary>
/// fetches single records as per the predicate condition
/// </summary>
/// <param name="where"></param>
/// <returns></returns>
public T Get(Expression<Func<T, bool>> where)
return dbset.Where(where).FirstOrDefault<T>();
现在的重点是如何在控制器中访问此存储库模式，我们开始：
1.你有用户模型：
public partial class User
public int Id get; set;
public string Name get; set;
2。现在您必须创建 UserModel 的存储库类
public class UserRepository : Repository<User>, IUserRepository
private Database_DBEntities dataContext;
protected IDatabaseFactory DatabaseFactory
get;
private set;
public UserRepository(IDatabaseFactory databaseFactory)
: base(databaseFactory)
DatabaseFactory = databaseFactory;
protected Database_DBEntities DataContext
get return dataContext ?? (dataContext = DatabaseFactory.Get());
public interface IUserRepository : IRepository<User>
3.现在您必须使用所有 CRUD 方法创建 UserService 接口 (IUserService.cs)：
public interface IUserService
#region User Details
List<User> GetAllUsers();
int SaveUserDetails(User Usermodel);
int UpdateUserDetails(User Usermodel);
int DeleteUserDetails(int Id);
#endregion
4.现在您必须使用所有 CRUD 方法创建用户服务接口 (UserService.cs)：
public class UserService : IUserService
IUserRepository _userRepository;
public UserService()
public UserService(IUserRepository userRepository)
this._userRepository = userRepository;
public List<User> GetAllUsers()
try
IEnumerable<User> liUser = _userRepository.GetAll();
return liUser.ToList();
catch (Exception ex)
throw ex;
/// <summary>
/// Saves the User details.
/// </summary>
/// <param name="User">The deptmodel.</param>
/// <returns></returns>
public int SaveUserDetails(User Usermodel)
try
if (Usermodel != null)
_userRepository.Add(Usermodel);
return 1;
else
return 0;
catch
throw;
/// <summary>
/// Updates the User details.
/// </summary>
/// <param name="User">The deptmodel.</param>
/// <returns></returns>
public int UpdateUserDetails(User Usermodel)
try
if (Usermodel != null)
_userRepository.Update(Usermodel);
return 1;
else
return 0;
catch
throw;
/// <summary>
/// Deletes the User details.
/// </summary>
/// <param name="Id">The code identifier.</param>
/// <returns></returns>
public int DeleteUserDetails(int Id)
try
User Usermodel = _userRepository.GetById(Id);
if (Usermodel != null)
_userRepository.Delete(Usermodel);
return 1;
else
return 0;
catch
throw;
5.现在你已经为你的存储库模式设置好了，你可以访问用户控制器中的所有数据：
//Here is the User Controller
public class UserProfileController : Controller
IUserService _userservice;
public CustomerProfileController(IUserService userservice)
this._userservice = userservice;
[HttpPost]
public ActionResult GetAllUsers(int id)
User objUser=new User();
objUser = _userservice.GetAllUsers().Where(x => x.Id == id).FirstOrDefault();
干杯！！
【讨论】：
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