Asp.Net.Core-EF.Core-DbFirst-.Net.Test.Sdk

An example of Asp.Net core web api using Entity Framework core, database first as well as .Net Test SDK and auto mapping.

This project is built with VS2019

Requirement

Technical Requirement:

AspnetCore EF Core .netStandard and Microsoft.NET.Test.Sdk.

Business Requirement:

• An user management web api solution that can add, update, delete and query users to a database.
• The Users are broken in to two types: Managers and Clients.
• Managers will have an additional 'Position' property (Junior, Senior) and Clients will have an int 'Level' property.
• Unit test the api controller.

Database design

• Since the Managers and Clients share most of their properties, we have a 'base' table Users.

• Both the Managers and Clients table have a foreign key that points to the Users table, these are one-one relationship.

• One manager can manage many clients, while one client only belongs to one manager, therefore Managers and Clients are one-many relationship.

• We also want to demostrate how to handle the 'base type' scenario in the project, where the Users will be implemented as a base type of * Managers and Clients.

  

Lets code!

Create UserManagement.UserAPI

Create asp.net core web api

choose location

select API project

The new project may look like this:

Install Entity Framework

Open Tools -> NuGet Package Manager -> Package Manager Console.

Run the following commands one by one:

Install-Package Microsoft.EntityFrameworkCore.SqlServer
Install-Package Microsoft.EntityFrameworkCore.Tools –Pre
Install-Package Microsoft.EntityFrameworkCore.SqlServer.Design

Create Models

Create a folder Models in the project.

Again, open Tools -> NuGet Package Manager -> Package Manager Console.

Run (You need to change database connection string accordingly)

Scaffold-DbContext "Server=(local)\SqlExpress;Database=UserManagement;UID=sa;PWD=sa12345;" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models

Now the code has models in it:

Config models

Delete the entire method OnConfiguring() in UserManagementContext.cs.

Open Startup.cs, and add this line of code at the end of ConfigureServices():

services.AddDbContext<UserManagementContext>(item => item.UseSqlServer(Configuration.GetConnectionString("UserManagementConnection")));

Open appsettings.json, modify it as:

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "AllowedHosts": "*",
  "ConnectionStrings": {
    "DomainConnection": "Server=(local)\\SqlExpress;Database=UserManagement;UID=sa;PWD=sa12345;"
  }
}

Create controller

Right click on Controllers folder, 'Add -> Controller...'.

Select 'API Controller with read/write actions'.

Click 'Add'.

Enter 'UserAPIController'. UserAPIController.cs is created in Controllers.

Create ViewModels

ViewModels are used to represent the data structure that sent to UI.

With Entity Framework, it's easy to implement a 'Table Per Hierarchy' relationship and 'Table Per Type' relationship:

https://docs.microsoft.com/en-us/ef/ef6/modeling/designer/inheritance/tph?redirectedfrom=MSDN
https://docs.microsoft.com/en-us/ef/ef6/modeling/designer/inheritance/tpt

However, this is untrue for Entity Framework Core. ViewModels are typically used to represent data to view, by doing this, we can tailor-made data structure for view to bind. Here, it's just some simple viewmodel examples, which look similar to models.

Use AutoMaper

AutoMaper is used to simplify the data convertion between models and viewmodels. However, you can write your own mapping logic.

Testability

In order to increase the testability of the controller, the dependencies of it are injected in Startup.cs:

// This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            // Auto Mapper Configurations
            var mappingConfig = new MapperConfiguration(mc =>
            {
                mc.AddProfile(new MappingProfile());
            });

            IMapper mapper = mappingConfig.CreateMapper();
            services.AddSingleton(mapper);

            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);

            services.AddDbContext<UserManagementContext>(item => item.UseSqlServer(Configuration.GetConnectionString("UserManagementConnection")));
            services.AddScoped<IUserRepository, UserRepository>();
            
            services.AddControllers();
        }

Unit Test

Unit test is easy with xUnit, NUnit or MS Unit Test.