public class DataPetapoco
    {
     public Database Db()
      {
        string serverName = ".\SQLEXPRESS;";
        string dbName = "db";
        string username = "user";
        string password = "123";

        var connectionstring = "Data Source=" + serverName +
                         ";Initial Catalog=" + dbName +
                         ";User ID=" + username +
                         ";Password=" + password +
                         ";Max Pool Size=200;Pooling=true" +
                         ";Connect Timeout=20";

        return new Database(connectionstring , "System.Data.SqlClient");
    }
}

var res = DataPetapoco.Db().Fetch<ProductViewModel>("select * from table");