I am new to EF core and I'm trying to get it to work with my ASP.NET Core project.
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
The problematic code in 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));
}
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");
}
All my research online points to missing references, but I can't seem to find out which one I am missing (see image).
First we install the Microsoft.EntityFrameworkCore.SqlServer NuGet Package:
PM > Install-Package Microsoft.EntityFrameworkCore.SqlServer
Then, after importing the namespace with
using Microsoft.EntityFrameworkCore;
we add the database context:
services.AddDbContext<AspDbContext>(options =>
options.UseSqlServer(config.GetConnectionString("optimumDB")));