实体框架核心:DbContextOptionsBuilder 不包含“usesqlserver"的定义并且没有扩展方法“usesqlserver"

本文介绍了实体框架核心:DbContextOptionsBuilder 不包含“usesqlserver"的定义并且没有扩展方法“usesqlserver"的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我是 EF Core 的新手，我正在尝试让它与我的 ASP.NET Core 项目一起工作.

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 配置为使用来自配置的连接字符串时，我在 startup.cs 中收到上述错误.我正在关注本教程.

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.

有问题的代码在startup.cs:

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)); }

UseSqlServer 方法如果我直接放到上下文中就可以识别:

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"); }

我所有的在线研究都指向缺失的参考文献，但我似乎无法找出我遗漏了哪一个 (见图片).

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

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

First we install the Microsoft.EntityFrameworkCore.SqlServer NuGet Package:

PM > Install-Package Microsoft.EntityFrameworkCore.SqlServer

然后，导入命名空间后

using Microsoft.EntityFrameworkCore;

我们添加数据库上下文:

we add the database context:

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