没有数据库提供商配置EF7 [英] No database providers are configured EF7

问题描述

我似乎得到该错误消息使用实体框架7和MVC6

I seem to be getting this error message when using Entity Framework 7 and MVC6

System.InvalidOperationException没有数据库提供商配置时。
通过在
的DbContext类或AddDbContext方法覆盖OnConfiguring设置
服务时，配置数据库提供商。

System.InvalidOperationException No database providers are configured. Configure a database provider by overriding OnConfiguring in your DbContext class or in the AddDbContext method when setting up services.

我相信我所做的一切都是我应该做，所以也许它的一个bug。我使用实体框架的版本7.0.0-同β7。

I believe i have done everything i am supposed to be doing, so maybe its a bug. I am using version 7.0.0-beta7 of Entity Framework.

我安装我的DbContext，需要在6的EntityFramework的接口，所以我可以嘲笑的DbContext（单元测试）。我的服务把接口作为一个构造函数和我在MVC 6设置DI

I have setup my DbContext, an interface so i can mock DbContext (was needed in EntityFramework 6 for unit testing). My services take the interface as a constructor and i have setup DI in MVC 6.

在我Startup.cs文件我有以下

In my Startup.cs file i have the following

public void ConfigureServices(IServiceCollection services)
{
    // entity framework
    services.AddEntityFramework()
        .AddSqlServer()
        .AddDbContext<MyDbContext>(options =>
            options.UseSqlServer(Configuration["Data:MyConnection:ConnectionString"])
        );

    // Add MVC services to the services container.
    services.AddMvc();

    // new context on each request
    services.AddScoped<IMyDbContext, MyDbContext>();
}

我已经检查了我的connectionString并返回一个有效的连接。我还检查了我的服务的对象是被注入，它不为空，所以都应该的工作，。

I have checked my connectionString and that is returning a valid connection. I have also checked in my service that the object is being injected, and it is not null, so that should all work.

我的config.json文件看起来像这样

My config.json file looks like this

{
    "Data": {
        "MyConnection": {
            "ConnectionString": "Server=(local);Database=XXXX;Trusted_Connection=True;"
        }
    }
}

我的DbContext不会覆盖OnConfiguring方法，因为我相信它不需要像我这样做以上这一切？我对吗？我在想什么？在许多不同的网站看了看，我猜一些正在使用的旧代码，因为一些方法不存在和其他网站有一样我有什么。

My DbContext does not override the OnConfiguring method, because i believe it is not needed as i am doing it all as above? Am i right? What am i missing? Looked at lots of different websites, i guess some are using old code, because some methods dont exist and other websites have the same as what i have.

推荐答案

设置如下图所示的MyDbContext注入在Startup.cs AddDbContext（）调用定义的选项参数。

Setup your MyDbContext shown below to inject the options parameter defined in Startup.cs AddDbContext() call.

public MyDbContext(DbContextOptions options)
: base(options)
{ }

这将允许您从配置（config.json）连接字符串传递到方法调用options.UseSqlServer（）

This will allow you to pass your connection string from the Configuration (config.json) into the method call options.UseSqlServer()

services.AddEntityFramework()
    .AddSqlServer()
    .AddDbContext<MyDbContext>(options => options.UseSqlServer(Configuration["Data:MyConnection:ConnectionString"]));

我遇到同样的问题，当我有我的解决方案分成单独的项目网站，BL和DAL

I encountered the same problem when I had to split my solution into separate projects Web, BL, and DAL.

这篇关于没有数据库提供商配置EF7的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！