我的 MVC 应用程序无法识别数据库连接

Question

In my mvc application, everything was working fine before but when i made some changes (the database name, user id & password) in the Connection string in the App.Config, my application is not recognizing anymore the database connection.

<!-- DEVELOPPEMENT ORIOLIS -->
<add name="DEAXIMAEntities" connectionString="metadata=res://*/DeAximaDataModel.csdl|res://*/DeAximaDataModel.ssdl|res://*/DeAximaDataModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=localhost\SQLEXPRESS;initial catalog=AXIMADB;persist security info=True;user id=****;password=****;MultipleActiveResultSets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />

it shows me the error like this everywhere i'm using my database connnection variable

using System.Web.Mvc;
using DAL;
using System;
using MvcAppDE.Fonctions;
using MvcAppDE.Filters;

namespace MvcAppDE.Controllers
{
    [IsRegisteredUser]
    public class HomeController : Commun.BaseController
    {
//it doesn't recognize anymore this database connection variable
        private DEAXIMAEntities db = new DEAXIMAEntities(); 
        private readonly string user = Environment.UserName;
        private string GetTitre() => "Bonjour " + db.UTILISATEUR.Find(user).UTILISATEUR_PRENOM;
       // private int dmCount = BaO.DemandesCount();
        private readonly int dmECCount = BaO.DemandesECCount();
    }
}

so i ended up getting this same error where it says CS0246 C# The type or namespace name could not be found (are you missing a using directive or an assembly reference?)

I've been trying to find the answer by looking at all the related questions on this forum but i haven't found the suitable solution yet.

PS: I'm a beginner in mvc asp .net so couldn't really figure it out by myself. thanks for your help in advance!

Answer 1

1.Go to Edmx file

2.expand edmx file & select.context.cs file -- double click

namespace DeAximaDataModel { 
  public partial class DEAXIMAEntities  : DbContext {
    public DEAXIMAEntities () : base("name=DEAXIMAEntities") // this name only u should give in controllers
    {

    } 
  } 
}

Answer 2

Just for the people looking for the answer in the future!

when i was remodifying the App.config in my application, i don't know why but the visual studio had emptied the.context.cs file(found it after expanding the.EDMX file) whhich made my database connection unfoundable. I somehow recovered all the code from the backup folder and pasted it in the same file. so that it can finally work again without any errors.

thanks to all who helped me understand the problem and the concerned area in the project.