Code Town: mvc

Today we will create an asp.net core MVC application using EntityFramework and MySQL Database with Visual Studio 2019 for Mac.

This is a simple CRUD operation for an Employe using ASP.NET Core 3.1 and EntityFrameworkCore

Prerequisites:

Visual Studio 2019 IDE for Mac
Make sure you are running the latest .Net core 3.1
Install the latest DOTNET and EF CLI using this command: dotnet tool install --global dotnet ef
MySQL database should be installed on your Mac

Getting Started:

Open the Visual Studio 2019 for Mac and Create a New Project as below

Please select the .Net Core 3.1 as below

I created a new project with the Name, "DotNetCore" and below is the Solution structure which

is created by VS2019.

Let's install the few mandatory nuget packages as below

1. Microsoft.EntityFrameworkCore

2. Microsoft.EntityFrameworkCore.Design

3. Microsoft.EntityFrameworkCore.Tools

4. MySql.Data

5. MySql.Data.EntityFrameworkCore

Now let's add a New Class name "DotNetCoreDbContext" under the Models folder by right-clicking

and select Add New Class.

Now let's write the code for this class.

We have to inherit our class from the DbContext class by using Microsoft.EntityFrameworkCore

	using System;
	using Microsoft.EntityFrameworkCore;

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

view raw DotNetCoreDbContext.cs hosted with ❤ by GitHub

Now let's add a New Class name "Employee" under the Models folder.

	using System;
	using System.ComponentModel;
	using System.ComponentModel.DataAnnotations;

	namespace DotNetCore.Models
	{
	public class Employee
	{
	[Key]
	public int EmployeeID { get; set; }

	[Required(ErrorMessage ="Please enter the full name!")]
	[DisplayName("Full Name")]
	public string FullName { get; set; }

	[Required(ErrorMessage = "Please enter the employee code!")]
	[DisplayName("Employee Code")]
	public string EmpCode { get; set; }

	[Required(ErrorMessage = "Please enter the position!")]
	[DisplayName("Position")]
	public string Position { get; set; }

	[Required(ErrorMessage = "Please enter the location!")]
	[DisplayName("Location")]
	public string Location { get; set; }
	}
	}

view raw Employee.cs hosted with ❤ by GitHub

Now add our class into DotNetCoreDbContext as below

	using System;
	using Microsoft.EntityFrameworkCore;

	namespace DotNetCore.Models
	{
	public class DotNetCoreDbContext : DbContext
	{
	public DotNetCoreDbContext(DbContextOptions<DotNetCoreDbContext> options): base(options)
	{
	}
	public DbSet<Employee> Employees { get; set; }
	}
	}

view raw DotNetCoreDbContext.cs hosted with ❤ by GitHub

Now we need to write code for ConnectionStrings in appsettings.json file

and modify the Startup.cs file as below

	{
	"Logging": {
	"LogLevel": {
	"Default": "Information",
	"Microsoft": "Warning",
	"Microsoft.Hosting.Lifetime": "Information"
	}
	},
	"AllowedHosts": "*",
	"ConnectionStrings": {
	"DefaultConnection": "Server=localhost;Database=dotnetcore;Uid=root;Pwd=root@123;"
	}
	}

view raw appsettings.json hosted with ❤ by GitHub

	using System;
	using System.Collections.Generic;
	using System.Linq;
	using System.Threading.Tasks;
	using DotNetCore.Models;
	using Microsoft.AspNetCore.Builder;
	using Microsoft.AspNetCore.Hosting;
	using Microsoft.AspNetCore.HttpsPolicy;
	using Microsoft.Extensions.Configuration;
	using Microsoft.Extensions.DependencyInjection;
	using Microsoft.Extensions.Hosting;
	using Microsoft.EntityFrameworkCore;

	namespace DotNetCore
	{
	public class Startup
	{
	public Startup(IConfiguration configuration)
	{
	Configuration = configuration;
	}

	public IConfiguration Configuration { get; }

	// This method gets called by the runtime. Use this method to add services to the container.
	public void ConfigureServices(IServiceCollection services)
	{
	services.AddControllersWithViews();
	services.AddDbContext<DotNetCoreDbContext>(options => options.UseMySQL(Configuration.GetConnectionString("DefaultConnection")));
	}

	// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
	public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
	{
	if (env.IsDevelopment())
	{
	app.UseDeveloperExceptionPage();
	}
	else
	{
	app.UseExceptionHandler("/Home/Error");
	// The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
	app.UseHsts();
	}
	app.UseHttpsRedirection();
	app.UseStaticFiles();

	app.UseRouting();

	app.UseAuthorization();

	app.UseEndpoints(endpoints =>
	{
	endpoints.MapControllerRoute(
	name: "default",
	pattern: "{controller=Employee}/{action=Index}/{id?}");
	});
	}
	}
	}

view raw Startup.cs hosted with ❤ by GitHub

Next step to add the Migration to create the Database in MySql

Run below command w.r.t your project folder path on Terminal

To Add-Migration:

dotnet ef migrations add InitialCreate

To Update-Database

dotnet ef database update

To Remove-Migration:

dotnet ef migrations remove

After adding the Migration, we can see our database has been created into the MySql database

We can see our created database dotnetcore including the Employees table.

Now let's add the controller name "EmployeeController" using Scaffolding as below

We will use the same action for Create and Edit an Employee.

Let's write the code for AddOrEdit action into EmployeeController

	// GET: Employee/AddOrEdit
	public IActionResult AddOrEdit(int Id=0)
	{
	if(Id==0)
	return View(new Employee());
	else
	return View(_context.Employees.Find(Id));
	}

view raw EmployeeController.cs hosted with ❤ by GitHub

Now let's add the view page for AddOrEdit action under the Views/Employee folder

	@model DotNetCore.Models.Employee

	@{
	ViewData["Title"] = "Create";
	}

	<h4>Employee Form</h4>
	<hr />
	<div class="row">
	<div class="col-md-4">
	<form asp-action="AddOrEdit">
	<div asp-validation-summary="ModelOnly" class="text-danger"></div>
	<input type="hidden" asp-for="EmployeeID" />
	<div class="form-group">
	<label asp-for="FullName" class="control-label"></label>
	<input asp-for="FullName" class="form-control" />
	<span asp-validation-for="FullName" class="text-danger"></span>
	</div>
	<div class="row">
	<div class="form-group col-md-6">
	<label asp-for="EmpCode" class="control-label"></label>
	<input asp-for="EmpCode" class="form-control" />
	<span asp-validation-for="EmpCode" class="text-danger"></span>
	</div>
	<div class="form-group col-md-6">
	<label asp-for="Position" class="control-label"></label>
	<input asp-for="Position" class="form-control" />
	<span asp-validation-for="Position" class="text-danger"></span>
	</div>
	</div>
	<div class="form-group">
	<label asp-for="Location" class="control-label"></label>
	<input asp-for="Location" class="form-control" />
	<span asp-validation-for="Location" class="text-danger"></span>
	</div>
	<div class="form-row">
	<div class="form-group col-md-6">
	<input type="submit" value="Submit" class="btn btn-primary btn-block" />
	</div>
	<div class="form-group col-md-6">
	<a asp-action="Index" class="btn btn-secondary btn-block"><i class="fa fa-table"></i> Back to List</a>
	</div>
	</div>
	</form>
	</div>
	</div>



	@section Scripts {
	@{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
	}

view raw AddOrEdit.cshtml hosted with ❤ by GitHub

We have written the code to create and edit an employee, added the view page also.

Now let's build our solution and run the application.

Let's create 3-4 employees by entering the required fields as below

Let's write some action methods to Index, Details, and Delete an employee as well

	// GET: Employee
	public async Task<IActionResult> Index()
	{
	return View(await _context.Employees.ToListAsync());
	}

view raw EmployeeController.cs hosted with ❤ by GitHub

	// GET: Employee/Details/5
	public async Task<IActionResult> Details(int? id)
	{
	if (id == null)
	{
	return NotFound();
	}

	var employee = await _context.Employees
	.FirstOrDefaultAsync(m => m.EmployeeID == id);
	if (employee == null)
	{
	return NotFound();
	}

	return View(employee);
	}

view raw EmployeeController.cs hosted with ❤ by GitHub

	// GET: Employee/Delete/5
	public async Task<IActionResult> Delete(int? id)
	{
	var employee = await _context.Employees.FindAsync(id);
	_context.Employees.Remove(employee);
	await _context.SaveChangesAsync();
	return RedirectToAction(nameof(Index));

	}