Create Data with Entity Framework Core in ASP.NET Core 3 Web API

Create a database named LearnASPNETCoreWebAPIWithRealApps. This database have a table: Product table as below:

USE LearnASPNETMVCWithRealApps

/* Table structure for table `product` */

GO
CREATE TABLE Product (
    Id int IDENTITY(1,1) NOT NULL PRIMARY KEY,
	Name varchar(250) NULL,
	Price money NULL,
	Quantity int NULL,
	Status bit NOT NULL
)

/* Dumping data for table `product` */
GO
INSERT Product(Name, Price, Quantity, Status) VALUES('Name 1', 20.0000, 4, 1)
GO
INSERT Product(Name, Price, Quantity, Status) VALUES('Name 2', 12.0000, 8, 0)
GO
INSERT Product(Name, Price, Quantity, Status) VALUES('Name 3', 4.0000, 3, 1)
GO
INSERT Product(Name, Price, Quantity, Status) VALUES('Name 4', 17.0000, 8, 1)




On the Visual Studio, create new ASP.NET Core Web Application project

Input Project Name and select Project Location




Select Empty Template and click Create button to Finish

Structure of New Project




Use NuGet add Libraries need for Entity Framework Core as below:

  • Microsoft.EntityFrameworkCore
  • Microsoft.EntityFrameworkCore.Tools
  • Microsoft.EntityFrameworkCore.SqlServer
  • Microsoft.EntityFrameworkCore.Design
  • Microsoft.EntityFrameworkCore.Proxies

Select Project and right click to select Add\New Item Menu

Select Web\ASP.NET in left side. Select App Settings File item and click Add button to Finish

In appsettings.json file and new configurations as below:

{
  "ConnectionStrings": {
    "DefaultConnection": "Server=.;Database=LearnASPNETCoreWebAPIWithRealApps;user id=sa;password=123456"
  }
}




Create new folder named Models. In Models folder, create new entity class as below:

Create new class named Product.cs as below:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace LearnASPNETCore3WebAPIWithRealApps.Models
{
    public class Product
    {
        public int Id { get; set; }

        public string Name { get; set; }

        public decimal Price { get; set; }

        public int Quantity { get; set; }

        public bool Status { get; set; }
    }
}

In Models folder, create new class named DataContext.cs as below:

using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;

namespace LearnASPNETCore3WebAPIWithRealApps.Models
{
    public class DataContext : DbContext
    {
        public DataContext(DbContextOptions<DataContext> options)
            : base(options)
        {
        }

        public DbSet<Product> Product { get; set; }

    }
}




Open Startup.cs file and add new configurations as below:

using LearnASPNETCore3WebAPIWithRealApps.Models;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace LearnASPNETCore3WebAPIWithRealApps
{
    public class Startup
    {
        public IConfiguration configuration { get; }

        public Startup(IConfiguration _configuration)
        {
            configuration = _configuration;
        }

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers();

            var connectionString = configuration.GetConnectionString("DefaultConnection");
            services.AddDbContext<DataContext>(options => options.UseLazyLoadingProxies().UseSqlServer(connectionString));
        }

        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseRouting();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }
}




Create new folder named Controllers. In this folder, create new controller named ProductController.cs as below:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Threading.Tasks;
using LearnASPNETCore3WebAPIWithRealApps.Models;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace LearnASPNETCore3WebAPIWithRealApps.Controllers
{
    [Route("api/product")]
    public class ProductController : Controller
    {
        private DataContext db;

        public ProductController(DataContext _db) {
                db = _db;
        }

        [Consumes("application/json")]
        [Produces("application/json")]
        [HttpPost("create")]
        public async Task<IActionResult> Create([FromBody] Product product)
        {
            try
            {
                db.Product.Add(product);
                db.SaveChanges();
                return Ok(product);
            }
            catch
            {
                return BadRequest();
            }
        }

    }
}




Create Console App (.NET Framework) Project in Visual Studio.

Create Models folder in Console Application. In this folder, create new class named Product.cs as below:

Product Entity

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace LearnASPNETCore3WebAPIWithRealApps_Client.Models
{
    public class Product
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public decimal Price { get; set; }
        public int Quantity { get; set; }
        public bool Status { get; set; }
    }
}

ProductRestClientModel class contain methods call Web API. Add reference to System.Net.Http.Formatting library from Nuget Packages

using LearnASPNETCore3WebAPIWithRealApps_Client.Models;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Threading.Tasks;

namespace LearnASPNETCore3WebAPIWithRealApps_Client
{
    public class ProductRestClientModel
    {
        private string BASE_URL = "http://localhost:18942/api/product/";

        public Task<HttpResponseMessage> Create(Product product)
        {
            try
            {
                HttpClient client = new HttpClient();
                client.BaseAddress = new Uri(BASE_URL);
                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
                return client.PostAsJsonAsync("create", product);
            }
            catch
            {
                return null;
            }
        }

    }
}




using LearnASPNETCore3WebAPIWithRealApps_Client.Models;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;

namespace LearnASPNETCore3WebAPIWithRealApps_Client
{
    class Program
    {
        static void Main(string[] args)
        {
            var productRestClientModel = new ProductRestClientModel();
            var product = new Product()
            {
                Name = "name 5",
                Price = 12,
                Quantity = 3,
                Status = true
            };
            var httpResponseMessage = productRestClientModel.Create(product).Result;
            var productInfo = httpResponseMessage.Content.ReadAsAsync<Product>().Result;
            var httpStatusCode = httpResponseMessage.StatusCode;
            Console.WriteLine("Status Code: " + httpStatusCode);
            bool isSuccessStatusCode = httpResponseMessage.IsSuccessStatusCode;
            Console.WriteLine("IsSuccessStatusCode: " + isSuccessStatusCode);
            Console.WriteLine("New Product Information");
            Console.WriteLine("Id: " + productInfo.Id);
            Console.WriteLine("Name: " + productInfo.Name);
            Console.WriteLine("Price: " + productInfo.Price);
            Console.WriteLine("Quantity: " + productInfo.Quantity);
            Console.WriteLine("Status: " + productInfo.Status);

            Console.ReadLine();
        }
    }
}




Status Code: OK
IsSuccessStatusCode: True
New Product Information
Id: 2021
Name: name 5
Price: 12.0
Quantity: 3
Status: True