public void SavePolygon(FigureData polygon, string name) { var connection = PostgresConnection.GetInstance(); try { connection.Open(); string sql = "insert into polygons (name, type, x_coords, y_coords) " + "values (@name, @type, @x_coords, @y_coords)"; var command = new NpgsqlCommand(sql, connection); command.Parameters.AddWithValue("@name", name); command.Parameters.AddWithValue("@type", polygon.PolygonType); var dictionary = FigureData.GetArraysFromCoords(polygon.Coords); command.Parameters.AddWithValue("@x_coords", dictionary["xCoords"]); command.Parameters.AddWithValue("@y_coords", dictionary["yCoords"]); command.ExecuteNonQuery(); } catch (Exception e) { Console.WriteLine(e.Message); } finally { connection.Close(); } }