Question

我正在构建一个webbapplication来学习ASP.NET 5.我正在使用：

Visual Studio 2015社区

ASP.NET 5 RC1

MVC 6

实体框架7

问题是在创建我的dbcontext以将实体映射到数据库之后，应用程序由于一个争论而无法启动。请参阅下文并注意参数无效的其他信息（Nyckelordetstödsinte）：multipleactiverecordsets。我该如何解决这个问题？

当我将以下内容发表评论时，该项目能够运行：

AppController.cs

    public IActionResult Index()
    {
        //var textposts = _context.Textposts.OrderBy(t => t.UserName).ToList(); //here
        //return View(textposts); //here
        return View();
    }

ProjectContext.cs

    public class ProjectContext : DbContext
    {

    public ProjectContext()
    {
        //Create the database and execute migrations
        //Database.EnsureCreated(); //here
        //Database.Migrate();
    }

以下是有关问题和代码段的信息。

Error. EF7 DB argumentexception multipleactiverecordsets

我准备好了数据库并进行了初始迁移（使用“dnx ef迁移添加InitialDatabase”时创建了迁移文件夹并将cs文件添加到该文件夹中）

Startup.cs

public class Startup
{

    public static IConfigurationRoot Configuration;

    public Startup(IApplicationEnvironment appEnv)
    {
        var builder = new ConfigurationBuilder()
            .SetBasePath(appEnv.ApplicationBasePath)
            .AddJsonFile("config.json")
            .AddEnvironmentVariables();

        Configuration = builder.Build();
    }
    // This method gets called by the runtime. Use this method to add services to the container.
    // For more information on how to configure your application, visit http://go.microsoft.com/fwlink/?LinkID=398940
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMvc();

        services.AddEntityFramework()
            .AddSqlServer()
            .AddDbContext<ProjectContext>();

project.json

{
  "webroot":  "wwwroot",
  "version": "1.0.0-*",

  "compilationOptions": {
    "emitEntryPoint": true
  },

  "dependencies": {
    "EntityFramework.MicrosoftSqlServer": "7.0.0-rc1-final",
    "Microsoft.AspNet.IISPlatformHandler": "1.0.0-rc1-final",
    "Microsoft.AspNet.Mvc": "6.0.0-rc1-final",
    "Microsoft.AspNet.Mvc.TagHelpers": "6.0.0-rc1-final",
    "Microsoft.AspNet.Server.Kestrel": "1.0.0-rc1-final",
    "Microsoft.AspNet.StaticFiles": "1.0.0-rc1-final",
    "EntityFramework.Commands": "7.0.0-rc1-final"
  },

  "commands": {
    "web": "Microsoft.AspNet.Server.Kestrel",
    "ef": "EntityFramework.Commands"
  },

  "frameworks": {
    "dnx451": { },
    "dnxcore50": { }
  },

  "exclude": [
    "wwwroot",
    "node_modules"
  ],
  "publishExclude": [
    "**.user",
    "**.vspscc"
  ]
}

ProjectContext.cs

public class ProjectContext : DbContext
{

    public ProjectContext()
    {
        //Create the database and execute migrations
        //Database.EnsureCreated();
        //Database.Migrate();
    }

    public DbSet<Textpost> Textposts { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        var connString = Startup.Configuration["Data:ProjectContextConnection"];
        //Optionsbuilder exposes the entities, using SQL Server.
        //Other types of db servers could be shown here if configured, such as MongoDB
        optionsBuilder.UseSqlServer(connString);

        base.OnConfiguring(optionsBuilder);
    }
}

}

AppController.cs

public class AppController : Controller
{
    private IMailService _mailService;
    private ProjectContext _context;

    public AppController(IMailService service, ProjectContext context)
    {
        _mailService = service;
        _context = context;
    }

    //The request is called Index. No id parameter in here yet -> app/index/id
    public IActionResult Index()
    {
        var textposts = _context.Textposts.OrderBy(t => t.UserName).ToList();
        return View(textposts);
        //return View();
    }

此外，当我尝试使用dnx ef命令工具添加新的迁移时，显示短语“参数无效（Nyckelordetstödsinte）：multipleactiverecordsets”。

dnx ef migration add SecondMigration

编辑：我在config.json中的连接字符串

  "Data": {
    "ProjectContextConnection": "Server=(localdb)\\ProjectsV12;Database=ProjectDb;Trusted_Connection=True;MultipleActiveRecordSets=True;"

}

Answer 1

ErikEJ通过询问连接字符串来解决问题。

在关注如何设置数据库和连接字符串的教程之后，我现在将字符串的最后一部分从MultipleActiveRecordSets更改为MultipleActiveResultSets。也许第一个符号来自以前的版本，现在不支持。它现在正在工作，感谢小费和热烈的欢迎！

EF7 Database.EnsureCreated（）ArgumentException参数无效multipleactiverecordsets

1 个答案: