Method not found: Void Microsoft.EntityFrameworkCore.Design. Internal.DbContextOperations

I was working on this asp.net Core application and got this error below while trying to scaffold a new controller as seen below. I suspected the issue happened because I had updated a few packages in the project.
Scaffolding new controller asp.net core Microsoft.EntityFrameworkCore.Design

Error message

Method not found: 'Void Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations..ctor
(Microsoft.EntityFrameworkCore.Design.Internal.IOperationReporter, System.Reflection.Assembly, System.Reflection.Assembly)'.
   at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.b__6_0()
   at Microsoft.Extensions.CommandLineUtils.CommandLineApplication.Execute(String[] args)
   at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.Execute(String[] args)
   at Microsoft.VisualStudio.Web.CodeGeneration.CodeGenCommand.Execute(String[] args)

Solution

After a quick searching and reading a few post online, I stumbled upon this one post on Stackoverflow where someone had similar issue. So, below you will find exactly what I did to resolve that issue which was very simple.

  • I unload the project, Right click the project -> Unload Project
  • Next, Right click the unloaded project name and Edit the .csproj file
  • Find the ItemGroup section in the .csproj file as seen below and update the following
    
     <ItemGroup>
      <PackageReference Include="Microsoft.AspNetCore" Version="2.2.0" />
      <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.7" />
      <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="2.0.3" />
      <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="2.0.3" PrivateAssets="All" />
      <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="2.0.3" PrivateAssets="All" />
     </ItemGroup>
    
    
  • Once done updating the versions, right click the project name and reload it. Then, clean the solution and build the project afterwards. If this doesn’t work for you then downgrade to a lower version until you get it to work.

Having Website Traffic Drop After Switching To HTTPS? Don’t Panic

Things to keep in mind if you are working on a website and have your traffic drop after switching to HTTPS

Before I continue I want to make sure I address two points to make sure we’re on the same page.
First, by switching to HTTPS/SSL security on your website, you will sometimes experience a drop in the amount of indexed urls you had.
Secondly, You should always consider implementing SSL on your website. As a matter of fact the earlier the better. While, it’s true that not all websites will need to have SSL implemented, but for those that are housing personal information such as a user login data, and e-mail MUST absolutely consider using SSL.

About a few months ago I started working on optimizing the traffic to one of my website and things started to turn around. People started to find and visit the website on a daily basis. I was getting pretty good amount of traffic for a brand new site.

Use Google Search Console

Using Google search console, I setup the site, and submitted my links regularly. Gradually over time I could see most of the links submitted were being indexed. Well, I have this feature that requires payment to be accepted on the site, therefore, I had to make sure the site was secured.

The traffic drop after switching to HTTPS in no time

After I switched the paid feature and switch on to HTTPS, I started noticing a drop in the organic traffic to the site.
So, I went straight to the Google Search Console to analyse the traffic, and indeed, when I check the coverage tab, It was reported that my website search results essentially dropped to almost zero with only 30 valid urls and 420 excluded.
[Add pic here]Google Search Console coverage report

I was curious to learn more about those 420 excluded links, when I drilled down more into this, I noticed about 307 of pages were being excluded due to “Page with redirect”.
Google search displaying coverage report of total links excluded from index

I researched the web about possible cause of that issue knowing that I recently updated the site from HTTP to HTTPS and I have never setup any 301 redirects on these urls.

Google search displaying coverage report of links that are no longer indexed

Start Tracking the correct domain

If you find yourself in the same situation don’t panic. The issue simple and easy fix. What happened was that Google was tracking the regular links on the site and a user lands on those pages, they are being redirected to the secured links. Therefore, those regular links are dropped from being indexed. However, Google still tracking the secured links. In order to view the report on them, all you have to do is add the secured url to Google search console. It should show the correct stats about your indexes.
Right after the update on the Google Search Console, I was able to re-index and track the https://domain and I could see that site is indeed still showing up in the searches.
Google search displaying coverage report of click and links indexed

How To Quickly Create A New Database Using EntityFramework Core On ASP.Net Core

Last post I’ve gone over how to disable a specific user in ASP.NET Core Identity 2.0, so in this post here, we’ll take a look at how we can leverage Entity Framework to quickly create new databases in no time. Therefore, I will be creating an employee manager using ASP.NET Core 2.1 and Entity Framework (EF) core Code First approach. This employee manager tracks all employees and their respective department.

Prerequisites

Install .NET Core 2.1 SDK from here
Install the latest version of Visual Studio 2017 from here
SQL Server 2008 or above
Source Code
Before proceeding, I recommend you get the source code from GitHub.
Quick read & Credit to: Entity Framework Core on ASP.NET Core

Create the ASP.NET Core project

Open Visual Studio and select “File” > “New” > “Project”.

After selecting the project, a “New Project” dialog will open. Select “.NET Core” in the left panel inside the Visual C# menu.

Then, select “ASP.NET Core Web Application” from the available project types. Put the name of the project as “EmployeeManagerWithEFCore” and press “OK” to create the ASP.NET Core Project.

A new dialog box will open asking you to select the template to be used for the project. So, make sure to select the following:

  • Make sure that .NET Core and ASP.NET Core 2.1 are selected in the drop-down lists
  • Select the Web Application (Model-View-Controller) project template
  • Make sure that Authentication is set to No Authentication
  • Click OK

Selecting the correct project template

By default the “No Authentication” option will be selected, however, if you are required to add login, you can change that in the change authentication button and select Individual User Accounts . Since this tutorial is simply to show how to get started with EntityFramework Core, we’ll keep things simple and not required user to login in in order to add new employees.

To make sure the project is created correctly, let’s run it and make sure there’s no errors before we start adding the models.
Load asp.net net project to ensure it's working

Adding the necessary Models

  • Employee
  • Department

Now, that we know we have a working application, let’s add the models.
Right-click on the Models folder and select Add > Class.

Enter Employee.cs as the name and click OK as seen in the image below.

Replace the contents of the file with the following code:

using System.ComponentModel.DataAnnotations;

namespace EmployeeManagerWithEFCore.Models
{
    public class Employee
    {
        [Key]
        public int Id { get; set; }
        [Required]
        [MaxLength(60)]
        public string FirstName { get; set; }
        [MaxLength(60)]
        public string LastName { get; set; }
        [Required]
        public int Salary { get; set; }
        [Required]
        [MaxLength(20)]
        public string Title { get; set; }
    }
}

Next, right-click on the Models folder and select Add > Class.

Enter Department.cs as the name and click OK.

Replace the contents of the file with the following code:

using System;
using System.Collections.Generic;

namespace EmployeeManagerWithEFCore.Models
{
    public class Department
    {
        public Department()
        {
            Employees = new List();
        }
        public int Id { get; set; }
        public string Name { get; set; }
        public string Description { get; set; }
        public string MapIcon { get; set; }
        public bool Deleted { get; set; }
        public DateTime UpdatedAt { get; set; }
        public DateTime CreatedAt { get; set; }
        public virtual ICollection Employees { get; set; }
    }
}

Add ConnectionString

Now, let’s add a new connectionstring in the appSettings.json file to be use for the database as followed.

Add the DbContext

Right-click on the Models folder and select Add > Class.

Enter ApplicationDbContext.cs as the name and click OK.

Replace the contents of the file with the following code:

using Microsoft.EntityFrameworkCore;

namespace EmployeeManagerWithEFCore.Models
{
    public class ApplicationDbContext : DbContext
    {
        public ApplicationDbContext(DbContextOptions options)
            : base(options)
        { }

        public DbSet Employees { get; set; }
        public DbSet Departments { get; set; }

    }
}

Some key notes about the above code snippet:

The class ApplicationDbContext is derived from DbContext which is a class that manages the database connection.
The DbSet properties are used to map with the database tables.

Register the db context

Now, we can register the context via the service configuration in the startup.cs file as shown below.

We have everything we need in the project to build it and make sure there’s no error. Once done, we can start creating the database.

Add Database

Tools > NuGet Package Manager > Package Manager Console

Run the following commands:
In order to generate the database and add the necessary tables, we need to run migration commands from the package manager console.

In Visual Studio select Tools > NuGet Package Manager > Package Manager Console.
Run the following commands:

 Add-Migration InitialDatabaseCreation
 Update-Database

In case you run into some error as I did during in this step, simply close Visual Studio and re-open the project. Then, re-run add-migration again.

Voila, after closing and re-open Visual Studio, I was able to successfully run Migration as expected.

PM> Add-Migration
cmdlet Add-Migration at command pipeline position 1
Supply values for the following parameters:
Name: InitialDatabaseCreation
Microsoft.EntityFrameworkCore.Infrastructure[10403]
      Entity Framework Core 2.1.0-preview2-30571 initialized 'ApplicationDbContext' using provider 'Microsoft.EntityFrameworkCore.SqlServer' with options: None
To undo this action, use Remove-Migration.
PM> Update-Database
Microsoft.EntityFrameworkCore.Infrastructure[10403]
      Entity Framework Core 2.1.0-preview2-30571 initialized 'ApplicationDbContext' using provider 'Microsoft.EntityFrameworkCore.SqlServer' with options: None
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (447ms) [Parameters=[], CommandType='Text', CommandTimeout='60']
      CREATE DATABASE [EmployeeManagerWithEFCoreDB];
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (61ms) [Parameters=[], CommandType='Text', CommandTimeout='60']
      IF SERVERPROPERTY('EngineEdition') <> 5
      BEGIN
          ALTER DATABASE [EmployeeManagerWithEFCoreDB] SET READ_COMMITTED_SNAPSHOT ON;
      END;
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (5ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      CREATE TABLE [__EFMigrationsHistory] (
          [MigrationId] nvarchar(150) NOT NULL,
          [ProductVersion] nvarchar(32) NOT NULL,
          CONSTRAINT [PK___EFMigrationsHistory] PRIMARY KEY ([MigrationId])
      );
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (33ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      SELECT OBJECT_ID(N'[__EFMigrationsHistory]');
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (1ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      SELECT [MigrationId], [ProductVersion]
      FROM [__EFMigrationsHistory]
      ORDER BY [MigrationId];
Microsoft.EntityFrameworkCore.Migrations[20402]
      Applying migration '20190114032255_InitialDatabaseCreation'.
Applying migration '20190114032255_InitialDatabaseCreation'.
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (1ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      CREATE TABLE [Departments] (
          [Id] int NOT NULL IDENTITY,
          [Name] nvarchar(max) NULL,
          [Description] nvarchar(max) NULL,
          [MapIcon] nvarchar(max) NULL,
          [Deleted] bit NOT NULL,
          [UpdatedAt] datetime2 NOT NULL,
          [CreatedAt] datetime2 NOT NULL,
          CONSTRAINT [PK_Departments] PRIMARY KEY ([Id])
      );
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (2ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      CREATE TABLE [Employees] (
          [Id] int NOT NULL IDENTITY,
          [FirstName] nvarchar(60) NOT NULL,
          [LastName] nvarchar(60) NULL,
          [Salary] int NOT NULL,
          [Title] nvarchar(20) NOT NULL,
          [DepartmentId] int NULL,
          CONSTRAINT [PK_Employees] PRIMARY KEY ([Id]),
          CONSTRAINT [FK_Employees_Departments_DepartmentId] FOREIGN KEY ([DepartmentId]) REFERENCES [Departments] ([Id]) ON DELETE NO ACTION
      );
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (0ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      CREATE INDEX [IX_Employees_DepartmentId] ON [Employees] ([DepartmentId]);
Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (2ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
      INSERT INTO [__EFMigrationsHistory] ([MigrationId], [ProductVersion])
      VALUES (N'20190114032255_InitialDatabaseCreation', N'2.1.0-preview2-30571');
Done.
PM> 

To conclude, if you check in sql server management and load your local databases, we should be seeing the new database created.

Add Department and Employee controller as shown below.

Controller.
Select MVC Controller with views, using Entity Framework and click Add.
Set Model class to respective to the controller being created and Data context class to ApplicationDbContext.
Make sure to select the “_Layout.cshtml”
Click Add.

Once those controllers are created you should notice two files “DepartmentsController.cs”,”EmployeesController.cs” in the controller folder and the view folder for each of those controllers with with the necessary view pages with (.cshtml).

Let’s run the application and see what we get and start populating the database.

Example of the department creation page:

For simplicity, I have hard-coded the department to get the employees added to the department we have created. For production, you might want to add a dropdown list for user to select the department while creating the employee.