实体框架核心:DbContextOptionsBuilder不包含"usesqlserver"的定义，也不包含扩展方法"usesqlserver" [英] Entity Framework Core: DbContextOptionsBuilder does not contain a definition for 'usesqlserver' and no extension method 'usesqlserver'

问题描述

我是EF Core的新手，我正在尝试使其与我的ASP.NET Core项目一起使用.

I am new to EF core and I'm trying to get it to work with my ASP.NET Core project.

尝试将DbContext配置为使用config中的连接字符串时，在startup.cs中收到上述错误.我正在学习本教程: https://docs.microsoft .com/en-us/aspnet/core/data/ef-mvc/intro

I get the above error in my startup.cs when trying configure the DbContext to use a connection string from config. I am following this tutorial: https://docs.microsoft.com/en-us/aspnet/core/data/ef-mvc/intro

startup.cs中的有问题的代码:

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));
        }

如果将UseSqlServer方法直接放在上下文中，则可以识别该方法:

The UseSqlServer method is recognized if I put it directly into the context:

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");
        }

我在网上进行的所有研究都指向缺少参考文献，但我似乎找不到我缺少的参考文献(查看图片).

All my research online points to missing references, but I can't seem to find out which one I am missing (see image).

推荐答案

这是项目系统中的一个已知问题.参见 dotnet/project-system#1741

This is a known issue in the project system. See dotnet/project-system#1741

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