Store / Retrieve ConnectionString from appSettings.json in ASP.net Core 2 MVC app

Question

I'm looking for the best practice way to store a connection string in appsettings.json in a .net Core 2 MVC app (like you do in web.config in MVC 5).

I want to use Dapper not EF (I found many EF examples).

Something like this:

{
  "ConnectionStrings": {
    "myDatabase": "Server=.;Database=myDatabase;Trusted_Connection=true;"
  },

  "Logging": {
    "IncludeScopes": false,
    "LogLevel": {
      "Default": "Warning"
    }
  }
}

Surely there are many examples online? Nothing I can find that is for .net core 2.0.

Several things have changed between 1 and 2 and I want to ensure I'm using version 2 best practices.

I've found this - but it seems to be .net core 1: Visual Studio 2017 - MVC Core - Part 05 - Connection String from appsettings.json

This uses key value pair appsettings - not the connectionstrings: Read AppSettings in ASP.NET Core 2.0

Again it's unclear if this is .net Core 1 or 2: Net Core Connection String Dapper visual studio 2017

Answer 1

Just put like shown below in appsettings.json.

"ConnectionStrings": {
    "DefaultConnection": "Data Source=;Initial Catalog=;Persist Security Info=True;User ID=; Password=;"
}

In Startup.cs fetch it as mentioned below:

public class Startup
{
    public Startup(IHostingEnvironment env)
    {
        var builder = new ConfigurationBuilder()
            .SetBasePath(env.ContentRootPath)
            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
            .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true);

        builder.AddEnvironmentVariables();
        Configuration = builder.Build();
    }

    public IConfigurationRoot Configuration { get; }
}

Use dependency injection to inject configuration in controller like mentioned below:

public class MyController : Controller
{
    private readonly IConfiguration _configuration;
    private string connectionString;

    public MyController(IConfiguration configuration) 
    {
        _configuration = configuration;

        connectionString = _configuration.GetConnectionString("DefaultConnection");
    }
}