DDD-EF-数据仓储

　　关系图

一、分层

二、DomainObjects构建edmx

三、EFRepositoryDemo.Domain定义仓储接口

 public interface IRepository<T>
         where T : class
     {
         void Add(T entity);
         void AddAll(IEnumerable<T> entities);
         void Update(T entity);
         void Update(IEnumerable<T> entities);
         void Delete(T entity);
         void Delete(Expression<Func<T, bool>> where);
         void DeleteAll(IEnumerable<T> entities);

         void Clear();
         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);
         IEnumerable<T> GetAllLazy();
     }

四、Infrastructure层 仓储的抽象基类（EF的CRUD）

Repository很明显的一个特征 是 内部没有SaveChanges()

 public abstract class EFRepositoryBase<T> where T : class
     {
         private Db1DbContext dataContext;
         private readonly DbSet<T> dbset;

         protected IDatabaseFactory DatabaseFactory
         {
             get;
             private set;
         }

         protected Db1DbContext DataContext
         {
             get { return dataContext ?? (dataContext = DatabaseFactory.Get()); }
         }

         protected EFRepositoryBase(IDatabaseFactory databaseFactory)
         {
             DatabaseFactory = databaseFactory;
             dbset = DataContext.Set<T>();
         }

         public virtual void Add(T entity)
         {
             dbset.Add(entity);
         }

         //新增方法
         public virtual void AddAll(IEnumerable<T> entities)
         {
             dbset.AddRange(entities);
         }

         public virtual void Update(T entity)
         {
             dbset.Attach(entity);
             dataContext.Entry(entity).State = EntityState.Modified;
         }

         //新增方法
         public virtual void Update(IEnumerable<T> entities)
         {
             foreach (T obj in entities)
             {
                 dbset.Attach(obj);
                 dataContext.Entry(obj).State = EntityState.Modified;
             }
         }

         public virtual void Delete(T entity)
         {
             dbset.Remove(entity);
         }

         public virtual void Delete(Expression<Func<T, bool>> where)
         {
             IEnumerable<T> objects = dbset.Where<T>(where).AsEnumerable();
             dbset.RemoveRange(objects);
         }

         //新增方法
         public virtual void DeleteAll(IEnumerable<T> entities)
         {
             dbset.RemoveRange(entities);
         }

         public virtual void Clear()
         {
             throw new NotImplementedException();
         }

         public virtual T GetById(long id)
         {
             return dbset.Find(id);
         }

         public virtual T GetById(string id)
         {
             return dbset.Find(id);
         }

         public virtual IEnumerable<T> GetAll()
         {
             return dbset.ToList();
         }

         public virtual IEnumerable<T> GetMany(Expression<Func<T, bool>> where)
         {
             return dbset.Where(where).ToList();
         }

         public T Get(Expression<Func<T, bool>> where)
         {
             return dbset.Where(where).FirstOrDefault<T>();
         }

         public virtual IEnumerable<T> GetAllLazy()
         {
             return dbset;
         }

     }

五、Repository 

     public interface IStuEducationRepo : IRepository<TB_Stu_Education>
     {

     }

     public class StuEducationRepo : RepositoryBase<TB_Stu_Education>, IStuEducationRepo
     {
         public StuEducationRepo(IDatabaseFactory databaseFactory)
             : base(databaseFactory)
         {

         }

     }

六、工作单元

在进行数据库的CUD操作时，因为Repository内部没有做SaveChanges()操作

所以要增加工作单元，进行包裹

     public interface IUnitOfWork
     {
         void Commit();
         void CommitAsync();
     }

 public class UnitOfWork : IUnitOfWork
     {
         private readonly IDatabaseFactory databaseFactory;
         private Db1DbContext dataContext;

         public UnitOfWork(IDatabaseFactory databaseFactory)
         {
             this.databaseFactory = databaseFactory;
         }

         protected Db1DbContext DataContext
         {
             get { return dataContext ?? (dataContext = databaseFactory.Get()); }
         }

         public void Commit()
         {
             DataContext.SaveChanges();
         }

         public void CommitAsync()
         {
             DataContext.SaveChangesAsync();
         }

     }

七、Autofac注册

             var builder = new ContainerBuilder();
             builder.RegisterApiControllers(Assembly.GetExecutingAssembly());

             builder.RegisterType<DatabaseFactory>().As<IDatabaseFactory>().InstancePerLifetimeScope();
             builder.RegisterType<UnitOfWork>().As<IUnitOfWork>().InstancePerLifetimeScope();

             builder.RegisterAssemblyTypes(typeof(StuEducationRepo).Assembly)
                 .Where(t => t.Name.EndsWith("Repo"))
                 .AsImplementedInterfaces().InstancePerLifetimeScope();

             builder.RegisterWebApiFilterProvider(GlobalConfiguration.Configuration);
             IContainer container = builder.Build();
             var resolver = new AutofacWebApiDependencyResolver(container);

             // Configure Web API with the dependency resolver.
             GlobalConfiguration.Configuration.DependencyResolver = resolver;

八、调用示例

 // GET api/<controller>/5
         public string Get(int id)
         {

             var stuAccount = _stuAccountRepo.Get(p => p.UserId == );
             if (stuAccount != null)
             {
                 stuAccount.UserName = "张冬林Test";
             }

             var stuEducation = _stuEducationRepo.GetMany(p => p.UserId == );
             if (stuEducation != null && stuEducation.Count() > )
             {
                 foreach (var i in stuEducation)
                 {
                     i.ModifyDate = new DateTime(, , );
                 }
             }

             _unitOfWork.Commit();

             return "value";
         }

九、总结说明

　　1、Global Autofac注册，以保证在一次Http请求的生命周期内的DbContext是单例的

        builder.RegisterType<DatabaseFactory>().As<IDatabaseFactory>().InstancePerLifetimeScope();

        private Db1DbContext dataContext;

        public Db1DbContext Get()
        {
            return dataContext ?? (dataContext = new Db1DbContext());
        }

　　这样Repository和UnitOfWork的DbContext 是一个对象，即同一个数据库上下文。所以 实现了 CRUD 与 数据持久化 两个步骤的分离

        public virtual void Update(T entity)
        {
            dbset.Attach(entity);
            dataContext.Entry(entity).State = EntityState.Modified;
        }

        private readonly IDatabaseFactory databaseFactory;
        private Db1DbContext dataContext;

        public UnitOfWork(IDatabaseFactory databaseFactory)
        {
            this.databaseFactory = databaseFactory;
        }

        protected Db1DbContext DataContext
        {
            get { return dataContext ?? (dataContext = databaseFactory.Get()); }
        }

        public void Commit()
        {
            DataContext.SaveChanges();
        }

　2、Entity Framework本身就是一仓储，但DDD的这种设计并非画蛇添足。接口定义与代码实现的分离，可以不用关心ORM，可以不用关心是何种DB

　　附：源码下载