Here we will learn how to use Database First approach of Entity Framework for asp.net mvc application development. In asp.net mvc application we will create a new EmployeeController class and write code that retrieves Employee data and displays it in the browser using a view template. To implement this we are going to use Database First approach of Entity Framework for development.
In Database First approach, we need to have existing database and need to create business model from that we can use Database first approach. Before starting directly with developing in MVC lets start with Exploring Database first.
Here is database EmployeeDB which contains a single table EmployeeDetails that wolud be like as shown below
To get data from database here we are going to use ADO.NET Entity Data Model (Entity framework). To add this right click on Models Folder à Select Add à then select ADO.NET Entity Data Model in that template we are selecting database as EmployeeDB and selecting EmployeeDetails table that will be like as shown below
After adding model our entity will be like as shown below
After adding model build application and check structure that will be like as shown below
After adding ADO.NET Entity Data Model now we are going to add controller. For adding Controller just Right click on controller folder à select Add à select controller and create a new controller with name EmployeeController by selecting below properties. To add controller our settings should be like as shown below
Controller name: EmployeeController. (This is the default.)
Template: MVC Controller with read/write actions and views, using Entity Framework.
Model class: EmployeeDetail (Tutorial5.Models).
Data context class: EmployeeDBEntities (Tutorial5.Models).
Views: Razor (CSHTML). (The default.)
Note: Some time you will not able to see Model class that time you need to build application.
After clicking on Add button following files and folders will be created. An EmployeeController.cs file in the project's Controllers folder and an Employee folder in the project's Views folder with following files Create.cshtml, Delete.cshtml, Details.cshtml, Edit.cshtml and Index.cshtml in the new Views\ Employee folder that will be like as shown below
Our controller EmployeeControll.cs file will contain code like as shown below
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using Tutorial5.Models;
namespace Tutorial5.Controllers
{
public class EmployeeController : Controller
{
private EmployeeDBEntities db = newEmployeeDBEntities();
//
// GET: /Employee/
public ActionResult Index()
{
return View(db.EmployeeDetails.ToList());
}
//
// GET: /Employee/Details/5
public ActionResult Details(int id = 0)
{
EmployeeDetail employeedetail = db.EmployeeDetails.Find(id);
if (employeedetail == null)
{
return HttpNotFound();
}
return View(employeedetail);
}
//
// GET: /Employee/Create
public ActionResult Create()
{
return View();
}
//
// POST: /Employee/Create
[HttpPost]
public ActionResult Create(EmployeeDetail employeedetail)
{
if (ModelState.IsValid)
{
db.EmployeeDetails.Add(employeedetail);
db.SaveChanges();
return RedirectToAction("Index");
}
return View(employeedetail);
}
//
// GET: /Employee/Edit/5
public ActionResult Edit(int id = 0)
{
EmployeeDetail employeedetail = db.EmployeeDetails.Find(id);
if (employeedetail == null)
{
return HttpNotFound();
}
return View(employeedetail);
}
//
// POST: /Employee/Edit/5
[HttpPost]
public ActionResult Edit(EmployeeDetail employeedetail)
{
if (ModelState.IsValid)
{
db.Entry(employeedetail).State = EntityState.Modified;
db.SaveChanges();
return RedirectToAction("Index");
}
return View(employeedetail);
}
//
// GET: /Employee/Delete/5
public ActionResult Delete(int id = 0)
{
EmployeeDetail employeedetail = db.EmployeeDetails.Find(id);
if (employeedetail == null)
{
return HttpNotFound();
}
return View(employeedetail);
}
//
// POST: /Employee/Delete/5
[HttpPost, ActionName("Delete")]
public ActionResult Delete(int id, EmployeeDetail employeedetail)
{
employeedetail = db.EmployeeDetails.Find(id);
db.EmployeeDetails.Remove(employeedetail);
db.SaveChanges();
return RedirectToAction("Index");
}
protected override void Dispose(bool disposing)
{
db.Dispose();
base.Dispose(disposing);
}
}
}
ASP.NET MVC 4 automatically create CRUD (create, read, update, and delete) action methods and views for you (the automatic creation of CRUD action methods and views is known as scaffolding). You now have a fully functional MVC 4 web application that lets you create, list, edit, and Delete Employee entries.
Now just run application and access EmployeeController with action method /Index. First time you will access EmployeeController/Index Action method it will show Empty list because we have not added data to it. URL will be like http://localhost:19486/Employee/Index
Now click on Create New link to add new employee details that will open new screen to add employee details that will be like as shown below
After adding an Employee it will get redirect to Index page and display entire list which we have added
Selecting records from EmployeeDetails Table
Here it will show all records which we have recently entered.
