Npsql.EntityFramework7无法使用npgsql服务器

本文关键字：npgsql 服务器 EntityFramework7 Npsql | 更新日期: 2023-09-27 17:59:54

我对C#还很陌生。我在下面的.UseNpgsql(string connectionString)上看到了一些红色的歪歪扭扭（错误下划线）。悬停错误告诉我可能没有使用正确的using语句。

using Microsoft.Data.Entity;
namespace Something.Context {
    public class OauthTokenContext : DbContext
    {
        public DbSet<Model.OauthToken> OauthTokens { get; set; }
        protected override void OnConfiguring(DbContextOptionsBuilder builder)
        {
            var connectionString = @"Server=localhost; Port=1337; User Id=tinganho; Password=secret; Database=hello";
            builder.UseNpgsql(connectionString);
        }
    }
}

在我的project.json中，我有以下依赖项：

"dependencies": {
    "Npgsql.EntityFramework7": "3.1.0-unstable0038",
    "Npgsql": "3.1.0-unstable0038"
}

并且在startup.cs:中

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Microsoft.AspNet.Builder;
using Microsoft.AspNet.Hosting;
using Microsoft.AspNet.Http;
using Microsoft.Framework.ConfigurationModel;
using Microsoft.AspNet.Routing;
using System.Linq;
using Microsoft.Data.Entity;
using Microsoft.Framework.DependencyInjection;
using Npgsql;
using Npgsql.EntityFramework7;
using Something.Context;
using Something.Model;
namespace Something
{
    public class Startup
    {
        public Startup(IHostingEnvironment env)
        {
        }
        // This method gets called by a runtime.
        // Use this method to add services to the container
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddEntityFramework()
                .AddDbContext<OauthTokenContext>();
            services.AddMvc();
            // Uncomment the following line to add Web API services which makes it easier to port Web API 2 controllers.
            // You will also need to add the Microsoft.AspNet.Mvc.WebApiCompatShim package to the 'dependencies' section of project.json.
            // services.AddWebApiConventions();
        }
        public IConfiguration Configuration { get; set; }
        // Configure is called after ConfigureServices is called.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            // Configure the HTTP request pipeline.
            app.UseStaticFiles();
            // Add MVC to the request pipeline.
            app.UseMvc();
            // Add the following route for porting Web API 2 controllers.
            // routes.MapWebApiRoute("DefaultApi", "api/{controller}/{id?}");
        }
    }
}

当我在services.AddEntityFramework()之后加上.AddNpgsql()时，我得到：

System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.Framework.DependencyInjection.Abstractions' or one of its dependencies

Npsql.EntityFramework7无法使用npgsql服务器

您应该使用这种方法：

1） 进入启动。ConfigureServices仅添加服务。AddEntityFrameworkNpgsql（）；

 public void ConfigureServices(IServiceCollection services)
 {
        //...
        services.AddEntityFrameworkNpgsql();
}

2） into类继承DbContext:

public class DatabaseClass : DbContext 
{
    //...
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseNpgsql("my connection string");
    }
}
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