How To Create A Dbcontext Class In Mvc

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• Updated date Nov 01, 2019

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In this blog, you will learn about using DBContext Connect Database in ASP.NET MVC 5.

Continuing with the previous article, today, I'm sharing a simple example using DBContext Connect Database in ASP.NET MVC 5.

You can see my previous blogs below

• ASP.NET MVC 5 Hello World
• ASP.NET MVC 5 Create Shared Layout Razor & ViewStart
• ASP.NET MVC 5 Install Bootstrap

Installing Entity Framework 6.x

Tools->Nuget Package Manager

Entity Framework

It helps us to map relationship object in the database used in ADO.NET

Okay, we need to create a database in App_Data directory, so you right clickApp_Data->New Item

After that, you open Web.config in the project and add the below code to connect database.

1. <connectionStrings>
2.     <add name="demoASPEntities"  connectionString= "Data Source=(LocalDb)\MSSQLLocalDB;Initial Catalog=demomvc5;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\demomvc5.mdf"  providerName= "System.Data.SqlClient"  />
3. </connectionStrings>

Create models in ASP.Net MVC 5

In the picture above, we create a User table, so I will build the entity model for the User.

Click Models-> add class User.cs

1. using  System;
2. using  System.Collections.Generic;
3. using  System.Linq;
4. using  System.Web;
5. using  System.ComponentModel.DataAnnotations;
6. using  System.ComponentModel.DataAnnotations.Schema;
7. namespace  MVC5_HelloWorld.Models
8. {
9. public class  User
10.     {
11.         [Key, Column(Order = 1)]
12.         [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
13. public int  idUser { get ; set ; }
14. public string  Username { get ; set ; }
15. public string  Password { get ; set ; }
16. public int  Lever { get ; set ; }
17.     }
18. }

Create Class Connect Database extends DBContext

DBcontext is used in Entity Framework, it's a very important part to connect to a table in database and execute query (insert, update, delete)

Models/demoEntities.cs

1. using  System;
2. using  System.Collections.Generic;
3. using  System.Linq;
4. using  System.Web;
5. using  MVC5_HelloWorld.Models;
6. using  System.Data.Entity;
7. using  System.Data.Entity.ModelConfiguration.Conventions;
8. namespace  MVC5_HelloWorld.Models
9. {
10. public class  demoEntities : DbContext
11.     {
12. public  demoEntities() : base ( "demoASPEntities" )
13.         {
14.         }
15. public  DbSet<User> Users { get ; set ; }
16. protected override void  OnModelCreating(DbModelBuilder modelBuilder)
17.         {
18.             modelBuilder.Entity<User>().ToTable("Users" );
19.             modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
20. base .OnModelCreating(modelBuilder);
21.         }
22.     }
23. }

base("demoASPEntities")

The declaration name connect.

DbSet Users

We use the declaration table Users Controllesr/HomeController.cs

1. using  System;
2. using  System.Collections.Generic;
3. using  System.Linq;
4. using  System.Web;
5. using  System.Web.Mvc;
6. using  MVC5_HelloWorld.Models;
7. namespace  MVC5_HelloWorld.Controllers
8. {
9. public class  HomeController : Controller
10.     {
11. private  demoEntities _db = new  demoEntities();
13. public  ActionResult Index()
14.         {
15.             var data = (from sin  _db.Users select s).ToList();
16.             ViewBag.users = data;
17.              ViewBag.title ="MVC5 - Hello World" ;
18. return  View();
19.         }
20.     }
21. }

Views/Home/Index.cshtml edits the code below,

1. @model MVC5_HelloWorld.Models.User
2.     <divclass = "container" >
3.         <divclass = "row" >
4.             <divclass = "col-md-12" >
5.                 <h2>@ViewBag.title</h2>
6.                 <a href="https://hoanguyenit.com" class = "btn btn-success" >https://hoanguyenit.com</a>
7.                 <tableclass = "table table-bordered" >
8.                     @foreach  (var user in  ViewBag.users)
9.                     {
10.                     <tr>
11.                         <td>@user.Username</td>
12.                         <td>@user.Password</td>
13.                         <td>@{
14. if  (user.Lever == 1)
15.                             {
16.                                 <spanclass = "badge badge-danger" >Admin</span>
17.                             }
18. else
19.                             {
20.                                 <spanclass = "badge badge-warning" >Member</span>
21.                             }
22.                         }</td>
23.                     </tr>
24.                     }
25.                 </table>
26.             </div>
27.         </div>
28.     </div>

Demo

How To Create A Dbcontext Class In Mvc

Source: https://www.c-sharpcorner.com/blogs/asp-net-mvc-5-using-dbcontext-connect-database

Posted by: kennedyliaboarpood.blogspot.com

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