Asp.Net Mvc Database First Vs Code First Approach Complete Guide

ASP.NET MVC - Database First Approach

Step 1: Create a New ASP.NET MVC Project

1. Open Visual Studio.
2. Go to File -> New -> Project.
3. Select ASP.NET Web Application (.NET Framework), name it DBFirstDemo, and click Create.
4. Choose MVC template and ensure Authentication is set to No Authentication.

Step 2: Set Up SQL Server Database

1. LocalDB: Use LocalDB that comes with Visual Studio.

2. In Server Explorer, right-click on Data Connections and select Add Connection.

   • Server Name: (localdb)\mssqllocaldb.
   • Click Create Database, name it MySampleDB.
   • Click OK.

3. Create a table in your database using SQL Server Object Explorer:

   CREATE TABLE dbo.Users (
       Id INT PRIMARY KEY IDENTITY,
       Username NVARCHAR(50) NOT NULL,
       Email NVARCHAR(50) NOT NULL,
       Password NVARCHAR(50) NOT NULL
   )
   

Step 3: Add ADO.NET Entity Data Model

1. In the DBFirstDemo project, right-click on the Models folder and select Add -> New Item.
2. Choose ADO.NET Entity Data Model and name it UsersModel.edmx. Click Add.
3. Select EF Designer from database and click Next.
4. Click New Connection. Ensure you are connecting to MySampleDB.
5. Save the connection settings and click Next.
6. Select dbo.Users table and give the model namespace UsersModelNamespace. Click Finish.

After these steps, an edmx file will be generated along with a context class and strongly-typed entities.

Step 4: Create a Controller Using Entity Framework

1. Right-click on the Controllers folder, select Add -> Controller.
2. Choose MVC 5 Controller with views, using Entity Framework.
3. Select User (UsersModelNamespace.UsersModel) as the model class.
4. Select UsersModelNamespace.UsersDBEntities as the data context class.
5. Name the controller UserController.

This will create a controller and views handling CRUD operations for the Users table.

Step 5: Run the Application

1. Press F5 or click on Start Debugging to run the application.
2. Navigate to /user (e.g., http://localhost:xyz/user) and test CRUD functionalities.

ASP.NET MVC - Code First Approach

Step 1: Create a New ASP.NET MVC Project

1. Open Visual Studio.
2. Go to File -> New -> Project.
3. Select ASP.NET Web Application (.NET Framework), name it CFDemo, and click Create.
4. Choose MVC template and ensure Authentication is set to No Authentication.

Step 2: Define a Model Class

In the Models folder, add a new class User.cs:

public class User
{
    public int Id { get; set; }
    public string Username { get; set; }
    public string Email { get; set; }
    public string Password { get; set; }
}

Step 3: Create DbContext Class

In the Models folder, add a new class UsersDbContext.cs:

using System.Data.Entity;

namespace CFDemo.Models
{
    public class UsersDbContext : DbContext
    {
        public DbSet<User> Users { get; set; }

        // Constructor
        public UsersDbContext() : base("name=DefaultConnection")
        {}

        // Configuration
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.Entity<User>().ToTable("Users");
        }
    }
}

Step 4: Configure App.config (or Web.config)

Ensure there is a connection string named DefaultConnection in Web.config:

<connectionStrings>
    <add name="DefaultConnection" connectionString="Server=(localdb)\mssqllocaldb;Database=MyCodeFirstDB;Trusted_Connection=True;" providerName="System.Data.SqlClient" />
</connectionStrings>

Step 5: Enable Migrations

1. Open Package Manager Console (Tools -> NuGet Package Manager -> Package Manager Console).
2. Execute Enable-Migrations command.
3. Edit Configuration.cs file in Migrations folder to add initial migration:

internal sealed class Configuration : DbMigrationsConfiguration<CFDemo.Models.UsersDbContext>
{
    public Configuration()
    {
        AutomaticMigrationsEnabled = true;
    }

    protected override void Seed(CFDemo.Models.UsersDbContext context)
    {
        context.Users.Add(new User() { Username = "JohnDoe", Email = "john@example.com", Password = "John123" });
    }
}

Step 6: Generate and Apply Migrations

1. Execute Add-Migration InitialCreate to create initial migration.
2. Execute Update-Database to apply migration and create database.

Step 7: Create a Controller Using Entity Framework

1. Right-click on the Controllers folder, select Add -> Controller.
2. Choose MVC 5 Controller with views, using Entity Framework.
3. Select User (CFDemo.Models) as the model class and UsersDbContext (CFDemo.Models) as the data context class.
4. Name the controller UserController.

Step 8: Run the Application

1. Press F5 or click on Start Debugging to run the application.
2. Navigate to /user (e.g., http://localhost:xyz/user) and test CRUD functionalities.

Summary

• Database First Approach: You design the database first and then generate the model from the database. This is useful if you already have an existing database.

• Code First Approach: You start by defining POCO classes (models) and then the database is created based on these model definitions. This allows you to work entirely in code without worrying about designing the database manually.