{
  "DbConnectionStrings": [
    {
      "name": "mssql",
      "connectionString": "Data Source=localhost;Initial Catalog=Master;User Id=sa;Password=1234;",
      "providerName": "System.Data.SqlClient"
    },
    {
      "name": "mysql",
      "connectionString": "Data Source=localhost;Initial Catalog=user;User Id=root;Password=1234;",
      "providerName": "Pomelo.Data.MySql"
    },
    {
      "name": "sqlite",
      "connectionString": "Data Source=data.db",
      "providerName": "Microsoft.Data.Sqlite"
    },
    {
      "name": "pgsql",
      "connectionString": "Host=localhost;Database=postgres;Username=postgres;Password=1234;",
      "providerName": "Npgsql"
    }
  ],
  "DbProviderFactories": [
    {
      "name": "SqlClient Data Provider",
      "invariant": "System.Data.SqlClient",
      "description": ".Net Framework Data Provider for SqlServer",
      "type": "System.Data.SqlClient.SqlClientFactory, System.Data.SqlClient"
    },
    {
      "name": "MySQL Data Provider by Pomelo",
      "invariant": "Pomelo.Data.MySql",
      "description": ".Net Framework Data Provider for MySql",
      "type": "Pomelo.Data.MySql.MySqlClientFactory, Pomelo.Data.MySql"
    },
    {
      "name": "SQLite Data Provider",
      "invariant": "Microsoft.Data.Sqlite",
      "description": ".Net Framework Data Provider for SQLite",
      "type": "Microsoft.Data.Sqlite.SqliteFactory, Microsoft.Data.Sqlite"
    },
    {
      "name": "Npgsql Data Provider",
      "invariant": "Npgsql",
      "description": ".Net Framework Data Provider for PostgreSql",
      "type": "Npgsql.NpgsqlFactory, Npgsql"
    }
  ]
}

var builder = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
// add json file
.AddJsonFile("db.provider.json");

var config = builder.Build();

// Load DbProviders and DbConnectionStrings
DbProviderManager.LoadConfiguration(config);

DbConnectionStringSetting conn = DbConnectionStringManager.ConnectionStrings["sqlite"];

DbProviderFactory factory = DbProviderFactories.GetFactory(conn.ProviderName);

IDbConnection db = factory.CreateConnection();

db.ConnectionString = conn.ConnectionString;
db.Open();

var cmd = db.CreateCommand();
cmd.CommandText = "select datetime('now');";
var dt = cmd.ExecuteScalar();
System.Console.WriteLine(dt);

db.Close();