asp.net-core - Entity Framework 核心: DbContextOptionsBuilder does not contain a definition for 'usesqlserver' and no extension method 'usesqlserver'

Question

我是 EF core 的新手，我正在尝试让它与我的 ASP.NET Core 项目配合使用。

尝试将 DbContext 配置为使用配置中的连接字符串时，我在 startup.cs 中收到上述错误。我正在关注this tutorial .

有问题的代码位于 startup.cs 中:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.SpaServices.Webpack;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.EntityFrameworkCore;
using tracV2.models;
using tracV2.data;

namespace tracV2
{
    public class Startup
    {
        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            // Add framework services.
            services.AddMvc();

            services.AddSingleton<IConfiguration>(Configuration);

            string conn = Configuration.GetConnectionString("optimumDB");

            services.AddDbContext<tracContext>(options => options.usesqlserver(conn));
        }

如果我直接将 UseSqlServer 方法放入上下文中，它就会被识别:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;

namespace tracV2.data
{
    public class tracContext : DbContext
    {
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseSqlServer("myrealconnectionstring");
        }

我所有的在线研究都指向缺失的引用文献，但我似乎无法找出我缺失的引用文献 ( see image )。

Answer 1

首先我们安装Microsoft.EntityFrameworkCore.SqlServer NuGet 包:

PM > Install-Package Microsoft.EntityFrameworkCore.SqlServer

然后，在导入命名空间后

using Microsoft.EntityFrameworkCore;

我们添加数据库上下文:

services.AddDbContext<AspDbContext>(options =>
    options.UseSqlServer(config.GetConnectionString("optimumDB")));