How can I implement DbContext Connection String in .NET Core?

Question

My situation is quite similar to this link or at least my code is similar and I am trying to find a way to apply this same method in .NET Core syntax.

Pass connectio

Answer 1

Generally you are going to want to read it from config at start-up, and then use the connection string to configure an Entity Framework DbContext service for your process.

1) Add a line to your appsettings.json:

"DbConnectionString": "Server=s;Database=db;Trusted_Connection=True;",

2) Read the line in you Startup.cs class (after the Startup method is called to build the Configuration - so usually in the ConfigureServices method) like this:

var connection = Configuration["DbConnectionString"];

3) If using Entity Framework add a database context service (MyDbContext is the context class generated by EF). You also want to tell the built-in dependency injection how to instantiate your database context:

services.AddDbContext(options => options.UseSqlServer(connection));
services.AddScoped();

Where IMyDbContext is (at it's simplist) just an interface you've extracted from your MyDbContext

4) Now you can define your controller to take a MyDbContext and the DI will take care of building it and passing it in when the controller is invoked:

public MyController(IMyDbContext context)
{
    _context = context  // store for later use
}