使用不同的Database，有不同的DBcontext，根据不同的URL请求连接到它

Question

we actually have an online app, which include a ChatBot .

This chatbot can show us different informations from a database, like

Me: "What is the estimated budget for Projcet1"

Chat bot: "The estimated budget is 50k € for Project1"

Fine. Now, we will deploy this application for different companies. And each company have a different Database.

For those different Database (2 at the moment) I created 2 context. I have 2 models to interact with those database, and I can add Controller for every models.

services.AddDbContext<data_firstContext>(options =>
            {       
                options.UseMySQL(Configuration.GetConnectionString("Database1"));

            });

services.AddDbContext<data_secondContext>(options =>
                {       
                    options.UseMySQL(Configuration.GetConnectionString("Database2"));
    
                });

The question now is, how can I chose to connect either to the first database, or to the second database. I can send from the front-end, the URL header of the App or something like that, or just catch it somewhere I guess, but how can I switch from one to an other depending on the Url request, or something I give in parameter from the front-end. I looked online but none of what I've tried actually work. If someone have an idea, it'd really help me ! Thanks

Answer 1

Assuming you are using EF core, you don't have to pass any parameter as such from the UI. You can do that directly by defining different DBContext s and use them in the constructors of your services by using Dependency Injection . For eg:

Startup.cs:

services.AddDbContext<data_firstContext>(options =>
            {       
                options.UseMySQL(Configuration.GetConnectionString("Database1"));

            });

services.AddDbContext<data_secondContext>(options =>
                {       
                    options.UseMySQL(Configuration.GetConnectionString("Database2"));
    
                });

FirstDbContext.cs:

public class FirstDbContext : DbContext
{
    public DbSet<ViewModels.Tower> Towers { get; set; }
    public DbSet<ViewModels.Motherboard> Motherboards { get; set; }

    public FirstDbContext(DbContextOptions<FirstDbContext> options)
        : base(options)
    {
    }
}

AdminController.cs:

[Authorize(Policy = "RequireAdminRole")]
public class AdminController : Controller
{
    private readonly FirstDbContext _context;

    public AdminController(FirstDbContext context)
    {
        _context = context;
    }

    public IActionResult Index()
    {
        return View();
    }

    public IActionResult Towers()
    {
        var model = _context.Towers.ToList();
        return View(model);
    }
}

Check this out: Entity Framework Core Using multiple DbContexts