我是ASP.NET MVC的初学者,尝试使用Entity Framework Code-First进行数据库访问,但是我收到了一个错误。我在stackoverflow上看到了很多问题,但它们与我的情况无关。我的错误是。
类型' System.InvalidOperationException'的例外情况发生在EntityFramework.dll中但未在用户代码中处理
其他信息:无法完成操作。提供的SqlConnection不指定初始目录或AttachDBFileName。
在var brands = lensStoreDB.Brands.ToList();
行的LensStoreController.cs中
LensStoreController.cs
public ActionResult Index()
{
var brands = lensStoreDB.Brands.ToList();
return View(brands);
}
Brands.cs,Lenses.cs和Manufacturer.cs是我的Model类
Brand.cs
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web;
namespace EyeContactLens.Models
{
public class Brands
{
[Key]
public int BrandId { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public List<Lenses> Lenses { get; set; }
}
}
Lenses.cs
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web;
namespace EyeContactLens.Models
{
public class Lenses
{
[Key]
public int LensesId { get; set; }
public int BrandId { get; set; }
public int ManufacturerId { get; set; }
public string Title { get; set; }
public decimal Price { get; set; }
public string LensManuUrl { get; set; }
public Brands Brand { get; set; }
public Manufacturer Manufacturer { get; set; }
}
}
Manufacturer.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace EyeContactLens.Models
{
public class Manufacturer
{
public int ManufacturerId { get; set; }
public string Name { get; set; }
}
}
我还有一个班级SampleData.cs
,我希望在浏览器上显示其数据。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;
namespace EyeContactLens.Models
{
public class SampleData : DropCreateDatabaseIfModelChanges<EyeContactLensEntities>
{
protected override void Seed(EyeContactLensEntities context)
{
var brands = new List<Brands>
{
new Brands { Name = "Cooper Vision"},
new Brands { Name = "Fresh Kon"},
new Brands { Name = "Flexcon"},
new Brands { Name = "Avaira"},
};
var manufacturer = new List<Manufacturer>
{
new Manufacturer { Name = "Oculus"},
new Manufacturer { Name = "Alcon (CIBA Vision)"}
};
new List<Lenses>
{
new Lenses { Title = "Biofinity Contact Lens", Brand = brands.Single(b => b.Name == "Cooper Vision"), Price = 8.99M, Manufacturer = manufacturer.Single(a => a.Name == "Alcon (CIBA Vision)"), LensManuUrl = "/Content/Images/placeholder.gif" },
new Lenses { Title = "FreshKon A55", Brand = brands.Single(b => b.Name == "Fresh Kon"), Price = 18.99M, Manufacturer = manufacturer.Single(a => a.Name == "Oculus"), LensManuUrl = "/Content/Images/placeholder.gif" },
new Lenses { Title = "Flexcon Blue Tint UV Prolong wear (BUPW) (45%)", Brand = brands.Single(b => b.Name == "Flexcon"), Price = 81.99M, Manufacturer = manufacturer.Single(a => a.Name == "Oculus"), LensManuUrl = "/Content/Images/placeholder.gif" },
new Lenses { Title = "Frequency 55 Toric Contact Lens", Brand = brands.Single(b => b.Name == "Cooper Vision"), Price = 10.99M, Manufacturer = manufacturer.Single(a => a.Name == "Alcon (CIBA Vision)"), LensManuUrl = "/Content/Images/placeholder.gif" },
new Lenses { Title = "Freshkon N-Hance Toric", Brand = brands.Single(b => b.Name == "Fresh Kon"), Price = 11.99M, Manufacturer = manufacturer.Single(a => a.Name == "Oculus"), LensManuUrl = "/Content/Images/placeholder.gif" }
}.ForEach(a => context.Lenses.Add(a));
}
}
}
我还将EyeContactLensEntities.cs
用作DbContext
:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;
namespace EyeContactLens.Models
{
public class EyeContactLensEntities : DbContext
{
public DbSet<Lenses> Lenses { get; set; }
public DbSet<Brands> Brands { get; set; }
}
}
web.config
:
<connectionStrings>
<add name="EyeContactLensEntities" connectionString="Data Source=|DataDirectory|EyeContactLens.sdf" providerName="System.Data.SqlClient"/>
</connectionStrings>
的Global.asax.cs
protected void Application_Start()
{
System.Data.Entity.Database.SetInitializer(new Models.SampleData());
AreaRegistration.RegisterAllAreas();
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
}
答案 0 :(得分:0)
您的连接字符串错误。 您需要在配置字符串中提供的内容是数据源(例如SQL Server实例)和初始目录(例如该服务器上的数据库)。
可以使用Sql Server Management Studio打开.sdf,从那里你应该能够看到你需要连接到什么。
编辑: 有关如何使用SQL Server Management Studio执行此操作的链接: How do you open an SDF file (SQL Server Compact Edition)?
答案 1 :(得分:0)
您需要更改连接字符串中的providerName:
<connectionStrings>
<add name="EyeContactLensEntities"
connectionString="Data Source=|DataDirectory|EyeContactLens.sdf"
providerName="System.Data.SqlSqlServerCe.4.0"/>
</connectionStrings>
您需要安装SQL Server Compact EF Nuget包:
Install-Package EntityFramework.SqlServerCompact