public TestSingleInstanceClass() { try{ DatabaseConnectivity databaseCon = DatabaseConnectivity.Instance(); databaseCon.OpenConnection(); databaseCon.CloseConnection(); DatabaseConnectivity databaseCon2 = DatabaseConnectivity.Instance(); // DatabaseConnectivity databaseCon4 = DatabaseConnectivity.Instance(); Console.WriteLine("Print server name [databaseCon]: " + databaseCon.getServerName()); Console.WriteLine("Print server name [databaseCon2]: " + databaseCon2.getServerName()); // databaseCon2.getServerName(); } catch (Exception e) { Console.WriteLine("\nError Message: " + e); } }
public void Play() { DatabaseConnectivity databaseConnectivity = DatabaseConnectivity.Instance(); MySqlConnection conn = databaseConnectivity.MakeMySQLConnection(); if (databaseConnectivity.OpenConnection() == true) { Console.WriteLine("\nConnection is open now.\n"); } // //MYSql Select Operation // string SelectQuery = "SELECT * FROM authors"; // MySqlCommand MSCommand = new MySqlCommand(SelectQuery, conn); // MySqlDataReader MSDreader = MSCommand.ExecuteReader(); // Console.WriteLine("ID Author_Name Author_Interest"); // //Reading each row one at a time, unitl Read() method sends false flag(which mean the all the data has been finished iterating) // while(MSDreader.Read()) { // Console.WriteLine("| {0} | {1} {2} |", MSDreader.GetInt32(0), MSDreader.GetString(1), MSDreader.GetString(2)); // } // //MYSql Insert Operation // string InsertQuery = "INSERT INTO authors(name, genre) VALUES('Subin Bhattari', 'Love Story') "; // MySqlCommand MSCommandInsert = new MySqlCommand(InsertQuery, conn); // try // { // MSCommandInsert.ExecuteNonQuery(); // Console.WriteLine("Data inserted successfully."); // } catch (Exception e) { // Console.WriteLine($"\n {e} \n"); // } // //Creating Table with Foreign key constraint // string CreateTableQuery = "CREATE TABLE kitabs(id INTEGER PRIMARY KEY AUTO_INCREMENT, name TEXT, authorId INT UNIQUE, FOREIGN KEY (authorId) REFERENCES authors(id))"; // MySqlCommand MySqlCreateTableCmd = new MySqlCommand(CreateTableQuery, conn); // try { // MySqlCreateTableCmd.ExecuteNonQuery(); // Console.WriteLine("Table created successfully."); // } catch (Exception e) { // Console.WriteLine($"\n {e} \n"); // } // //Inserting 3 data into Table with foreign key constraint [Maxinum number of data entry using single query is 1000] // string Insert3DataQuery = "INSERT INTO kitabs(name, authorId) VALUES('Harry Potter', 1), ('Revolution 2020', 2), ('Summer Love', 3)"; // MySqlCommand MySqlCommandI3Q = new MySqlCommand(Insert3DataQuery, conn); // try { // MySqlCommandI3Q.ExecuteNonQuery(); // Console.WriteLine("\n3 data has been inserted successfully into kitabs table.\n"); // } catch(Exception e) { // Console.WriteLine($"\n {e} \n"); // } //Note: I am not doing DELETE and UPDATE query //Doing MYSQL prepared statements: Which will increase security and performance //Basically it is used in INSERT OPERATIONS // string PreparedInsertQuery = "INSERT INTO authors(name, genre) VALUES(@name, @genre)"; // MySqlCommand MSpiq = new MySqlCommand(PreparedInsertQuery, conn); // MSpiq.Parameters.AddWithValue("@name", "Vishen Lakhyani"); // MSpiq.Parameters.AddWithValue("@genre", "Personal Dpmnt"); // MSpiq.Prepare(); // try // { // MSpiq.ExecuteNonQuery(); // Console.WriteLine("Data inserted successfully using Prepare statement."); // } catch (Exception e) { // Console.WriteLine($"\n {e} \n"); // } //Delete Query string DeleteQuery = "DELETE FROM authors WHERE id=5"; MySqlCommand MSDeleteCmd = new MySqlCommand(DeleteQuery, conn); try { MSDeleteCmd.ExecuteNonQuery(); Console.WriteLine("\nId:5 Data is deleted successfully.\n"); } catch (Exception e) { Console.WriteLine($"\n {e} \n"); } if (databaseConnectivity.CloseConnection()) { Console.WriteLine("\nYou lost Database connection.\n "); } }