MVCTemplate/MVCTemplate.Data/Extensions/StartupExtensions.cs

using Microsoft.Extensions.DependencyInjection;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using MVCTemplate.Data.DbContexts;
using Microsoft.AspNetCore.Identity;

namespace MVCTemplate.Data.Extensions
{
    public class StartupExtensions
    {
        public static void ConfigureServices(IServiceCollection services)
        {
            var configuration = new ConfigurationBuilder()
                .AddJsonFile(path: "appsettings.json")
                .Build();
            services.AddDbContext<AppDbContext>(options =>
                options.UseSqlServer(
                    configuration.GetConnectionString("DefaultConnection")));
        }
    }
}