Question

我使用实体框架4.1代码第一种方法创建一个新的网络，使用单独的图层：

在模型层中，我定义了类模型

在数据层中，我定义了存储库类

在数据库层，我实现了存储库类。创建上下文，我实现了DbContext来自定义我自己的表。

最后，我将图层的引用添加到网站（表示层）。运行我的网站后，EF 4.1不会在App_Data文件夹中创建数据库。我想知道哪些步骤我做错了。请查看我的代码并给我一些建议。提前谢谢！

我只是添加我认为包含错误的类的代码。 Model层中的其他类模型和Data层中的类存储库与错误无关。所以我不在这里写。

的web.config：

<add name="ApplicationServices" connectionString="Data Source=DESKTOP\Neven;Initial Catalog=aspnetdb;Integrated Security=True" providerName="System.Data.SqlClient" />
      <add name="FashionShopData" connectionString="Data Source=|DataDirectory|FashionShopData.mdf;Initial Catalog=FashionShopData;Integrated Security=True" providerName="System.Data.SqlClient" />

在Global.asax中：

    protected void Application_Start()
        {

            AreaRegistration.RegisterAllAreas();

            RegisterGlobalFilters(GlobalFilters.Filters);
            RegisterRoutes(RouteTable.Routes);

            ModelMetadataProviders.Current = new MetadataProvider();
            InitialDatabase();
        }

private static void InitialDatabase()
        {
            var repositoryInitializer = new RepositoryInitializer();
            repositoryInitializer.Initialize();
        }

在数据库SQL层中：

上下文

    using System.ComponentModel.DataAnnotations;
using System.Data.Entity;
using FashionShop.Data.Repositories;
using FashionShop.Models;

namespace FashipShop.Data.Sql
{

    public partial class FashionShopContext : DbContext, IUnitOfWork
    {
        /// <summary>
        /// This method sets up the database appropriately for the available model objects.
        /// This method only sets up the data tier.  
        /// Any shared or model level requirements (data validations, etc) are on the model objects themselves.
        /// </summary>
        /// <param name="modelBuilder">The model builder object for creating the data model.</param>
        public FashionShopContext()
        : base("name=FashionShopData")
    {

    }
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {

            SetupUserEntity(modelBuilder);

            SetupCategoryEntity(modelBuilder);

            SetupProductEntity(modelBuilder);

            SetupOrderEntity(modelBuilder);

        }

        private static void SetupUserEntity(DbModelBuilder modelBuilder)
        {
            modelBuilder.Entity<User>().HasKey(r => r.UserId);
            modelBuilder.Entity<User>().Property(r => r.UserId).HasDatabaseGeneratedOption(
                DatabaseGeneratedOption.Identity);

            modelBuilder.Entity<User>().HasMany(o => o.Orders);

            modelBuilder.Entity<User>().Property(r => r.Email).IsRequired();
        }

        private static void SetupCategoryEntity(DbModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Category>().HasKey(c => c.CateId);
            modelBuilder.Entity<Category>().Property(c => c.CateId).HasDatabaseGeneratedOption(
                DatabaseGeneratedOption.Identity);
            modelBuilder.Entity<Category>().Property(c => c.ParentId).IsOptional();
            modelBuilder.Entity<Category>().HasMany(p => p.Products);
        }

        private static void SetupProductEntity(DbModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Product>().HasKey(p => p.ProductId);
            modelBuilder.Entity<Product>().Property(p => p.ProductId).HasDatabaseGeneratedOption(
                DatabaseGeneratedOption.Identity);

            modelBuilder.Entity<Product>().HasRequired(c => c.Category).WithRequiredPrincipal().WillCascadeOnDelete(true);
        }

        private static void SetupOrderEntity(DbModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Order>().HasKey(o => o.OrderId);
            modelBuilder.Entity<Order>().Property(o => o.OrderId).HasDatabaseGeneratedOption(
                DatabaseGeneratedOption.Identity);
            modelBuilder.Entity<Order>().HasMany(p => p.Products).WithMany(o => o.Orders).Map(op =>
                                                                                                  {
                                                                                                      op.ToTable(
                                                                                                          "ProductOrder");
                                                                                                      op.MapLeftKey(
                                                                                                          "OrderId");
                                                                                                      op.MapRightKey(
                                                                                                          "ProductId");
                                                                                                  });
        }

        public DbSet<User> Users { get; set; }

        public DbSet<Category> Categories { get; set; }

        public DbSet<Product> Products { get; set; }

        public DbSet<Order> ShoppingCarts { get; set; }

        void IUnitOfWork.SaveChanges()
        {
            base.SaveChanges();
        }
    }
}

存储库初始化代码：

    using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using FashionShop.Data.Repositories;

namespace FashipShop.Data.Sql
{
    public class RepositoryInitializer : IRepositoryInitializer
    {

        public RepositoryInitializer()
        {
            Database.DefaultConnectionFactory = new SqlConnectionFactory();
        }

        public void Initialize()
        {
            Database.SetInitializer(new CreateDatabaseIfNotExists<FashionShopContext>());
        }
    }
}

通用存储库：

    using System;
using System.Data;
using System.Linq;
using System.Linq.Expressions;
using FashionShop.Data.Repositories;


namespace FashipShop.Data.Sql.Repositories
{    
    public abstract class GenericRepository<T>: IGenericRepository<T> where T:class {
        protected IUnitOfWork UnitOfWork { get; set; }
        protected FashionShopContext Context { get { return (FashionShopContext)this.UnitOfWork; } }

        public GenericRepository(IUnitOfWork unitOfWork)
        {
            if (unitOfWork == null) throw new ArgumentNullException("unitOfWork");
            this.UnitOfWork = unitOfWork;
        }

        public virtual IQueryable<T> GetAll()
        {
            IQueryable<T> query  = Context.Set<T>();
            return query;
        }

        public IQueryable<T> FindBy(Expression<Func<T, bool>> predicate)
        {
            IQueryable<T> query = Context.Set<T>().Where(predicate);
            return query;
        }

        public virtual void Add(T entity)
        {
            Context.Set<T>().Add(entity);
            Context.SaveChanges();
        }

        public virtual void Delete(T entity)
        {
            Context.Set<T>().Remove(entity);
            Context.SaveChanges();
        }

        public virtual void Edit(T entity)
        {
            Context.Entry(entity).State = EntityState.Modified;
            Context.SaveChanges();
        }
    }



}

我发现了这个错误，因为我从不在我的表示层使用代码，因此EF不会初始化数据库，我需要添加

FashionShopContext context = new FashionShopContext(); 
context.Database.Initialize(true);

进入Application_Start（）。但在我改变代码之后又出现了另一个错误：

"A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server"

这是我使用的连接字符串：

<add name="FashionShopData" connectionString="Data Source=|DataDirectory|FashionShopData.mdf;Initial Catalog=FashionShopData;Integrated Security=True" providerName="System.Data.SqlClient" />

我的连接字符串是错误的吗？我该如何纠正呢？

Answer 1

尝试..

<add name="ContextName" connectionString="Data Source=ServerName;Initial Catalog=DBCataloName;Integrated Security=True;MultipleActiveResultSets=True;App=EntityFramework"
   providerName="System.Data.SqlClient" />

Answer 2

问题是启动连接字符串，您在DbContext派生类上设置。

应该如下所示。

public partial class FashionShopContext : DbContext, IUnitOfWork
{

   public static string ConnectionString { get; set; }

   public FashionShopContext() : base(ConnectionString ?? "FashionShopData")
    {

    }
}

<强> Global.asax中

protected void Application_Start()
{
FashionShopContext.ConnectionString = ConfigurationManager.ConnectionStrings["FashionShopData"].ConnectionString;
}

我希望这会对你有所帮助。

EF 4.1首先使用代码不创建新数据库

2 个答案: