Configure Database (Database First)

Configure Database using (Database First) has two cases

• case 1 - configure the database in first time when create new project.
• case 2 - update your code (models classes) if the database already configured before and the database had some changes.

Case 1 - Configure database first time

1- add those packages to your project dependances using Nuget package manager

• Microsoft.EntityFrameworkCore.SqlServer
• Microsoft.EntityFrameworkCore.Design
• Microsoft.EntityFrameworkCore.Tools

2- download the dotnet EF Tool globaly using this command

dotnet tool install --global dotnet-ef

3- execute the Scaffold command adding your connection string of your database and chose the output directory folder name

Scaffold-DbContext -Connection ["your connection string"] Microsoft.EntityFrameworkCore.SqlServer -OutputDir [out put folder name] -force

Example - here I chosed Models as an output directory folder

Scaffold-DbContext -Connection "Server=.\SQLEXPRESS;Database=Aspire;User Id=sa;password=*****;Trusted_Connection=True;MultipleActiveResultSets=true;" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models -force

4- change the connection string of your context class to be mapped to the name of connection string inside appsettings json file - steps:

• open your out put folder (for past example is Model folder) and open your context class (for past example is AspireContext)
• go to method OnConfiguring() and change the UseSqlServer from connection string to the name of the connection string in the app setting

example change code from

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            if (!optionsBuilder.IsConfigured)
            {
                optionsBuilder.UseSqlServer("Server=.\\SQLEXPRESS;Database=Aspire;User Id=sa;password=*****;Trusted_Connection=True;MultipleActiveResultSets=true;");
            }
        }

to

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            if (!optionsBuilder.IsConfigured)
            {
                optionsBuilder.UseSqlServer("Name=ELearningDB");
            }
        }

5- adding the dependancy of the DbContext in the program.cs

services.AddDbContext<AspireContext>(options =>
    options.UseSqlServer(configuration.GetConnectionString("ELearningDB")));

Case 2 - Update your code for any changes happend in Database

this case if the database already configured before and the database has some changes and you need to update your models classes to match the updates

just execute that command with your connection string name inside the appsettings json file

Scaffold-DbContext -Connection Name=[appsettings connection string name]  Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models -force

example

Scaffold-DbContext -Connection Name=ELearningDB  Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models -force