var host = "HostName";
var port = 3306;
var dataBase = "DatabaseName";
var userName = "UserName";
var password = "Password";

var connString = 
    $"Server={host};Database={dataBase};port={port}" +
    $";User Id={userName};password={password}";

var conn = new MySqlConnection(connString);
conn.Open();

var command = conn.CreateCommand();
command.CommandText = @"
  SELECT
    Language, Percentage
  FROM countrylanguage
  WHERE CountryCode = 'RUS'
  ORDER BY Percentage DESC";
var reader = command.ExecuteReader();
// Get the data
if (!reader.Read()) {
    return;
}

WriteLine(reader.GetString(0) + ": " + 
    reader.GetFloat("Percentage"));