RCM/RCM/DataSource/MySQL/MySQL.cs

using MySqlConnector;
using System;
using System.Collections.Generic;
using System.Windows.Forms;

namespace RCM {
    [DisplayName("MySQL/MariaDB")]
    [Serializable]
    public class MySQL : IDataSource {
        public string Title { get; set; }
        public HashSet<Guid> ExpandedNodes { get; } = new HashSet<Guid>();

        public string Host { get; set; }
        public string Username { get; set; }
        public string Password { get; set; }
        public string Database { get; set; }
        public string AESPassword { get; set; }

        [NonSerialized]
        private MySqlConnection _connection;
        [NonSerialized]
        private MySQLControl _control;

        public override string ToString() => Title;

        private MySqlConnection CreateConnection(string host, string username, string password, string database) {
            string[] hostport = host.Split(':');
            string port = hostport.Length > 1 ? hostport[1] : "3306";
            return new MySqlConnection(string.Format("server={0};port={1};user={2};password={3};database={4}", hostport[0], port, username, password, database));
        }

        private void OpenConnection() {
            if (_connection == null) {
                _connection = CreateConnection(Host, Username, Password, Database);
            }
            _connection.Open();
        }

        public Dictionary<Guid, IRecord> SelectAll() {
            Dictionary<Guid, IRecord> records = new Dictionary<Guid, IRecord>();
            OpenConnection();
            using (MySqlCommand command = new MySqlCommand("SELECT `data`, LENGTH(`data`) AS `datalength` FROM `data`", _connection))
            using (MySqlDataReader reader = command.ExecuteReader()) {
                while (reader.Read()) {
                    int dataBytesLength = reader.GetInt32(1);
                    byte[] dataBytes = new byte[dataBytesLength];
                    reader.GetBytes(0, 0, dataBytes, 0, dataBytesLength);
                    IRecord record = (IRecord)ConfigSerializer.DecryptObject(dataBytes, AESPassword);
                    records.Add(record.Id, record);
                }
            }
            _connection.Close();
            return records;
        }

        public void Insert(IRecord record) {
            OpenConnection();
            using (MySqlCommand command = new MySqlCommand("INSERT INTO `data` (`id`, `group`, `data`) VALUES (@id, @group, @data)", _connection)) {
                command.Parameters.AddWithValue("@id", record.Id.ToByteArray());
                if (record.GroupId == Guid.Empty) {
                    command.Parameters.AddWithValue("@group", null);
                } else {
                    command.Parameters.AddWithValue("@group", record.GroupId.ToByteArray());
                }
                command.Parameters.AddWithValue("@data", ConfigSerializer.EncryptObject(record, AESPassword));
                command.ExecuteNonQuery();
            }
            _connection.Close();
        }

        public void Update(IRecord record) {
            OpenConnection();
            using (MySqlCommand command = new MySqlCommand("UPDATE `data` SET `group` = @group, `data` = @data WHERE `id` = @id", _connection)) {
                if (record.GroupId == Guid.Empty) {
                    command.Parameters.AddWithValue("@group", null);
                } else {
                    command.Parameters.AddWithValue("@group", record.GroupId.ToByteArray());
                }
                command.Parameters.AddWithValue("@data", ConfigSerializer.EncryptObject(record, AESPassword));
                command.Parameters.AddWithValue("@id", record.Id.ToByteArray());
                command.ExecuteNonQuery();
            }
            _connection.Close();
        }

        public void Delete(IRecord record) {
            OpenConnection();
            using (MySqlCommand command = new MySqlCommand("DELETE FROM `data` WHERE `id` = @id", _connection)) {
                command.Parameters.AddWithValue("@id", record.Id.ToByteArray());
                command.ExecuteNonQuery();
            }
            _connection.Close();
        }

        public UserControl GetControl() {
            if (_control == null || _control.IsDisposed) {
                _control = new MySQLControl(this);
            }
            return _control;
        }

        public void UpdateFromControl() {
            Host = _control.textBoxHostAddress.Text;
            Username = _control.textBoxUsername.Text;
            Password = _control.textBoxPassword.Text;
            Database = _control.textBoxDatabase.Text;
            AESPassword = _control.textBoxEncPassword.Text;
            _connection = null;
        }

        public bool SchemaExists(string host, string username, string password, string database) {
            using (MySqlConnection tempConnection = CreateConnection(host, username, password, database)) {
                tempConnection.Open();
                using (MySqlCommand command = new MySqlCommand("SHOW TABLES LIKE \"data\"", tempConnection))
                using (MySqlDataReader reader = command.ExecuteReader()) {
                    return reader.HasRows;
                }
            }
        }

        public void CreateSchema(string host, string username, string password, string database) {
            using (MySqlConnection tempConnection = CreateConnection(host, username, password, database)) {
                tempConnection.Open();
                using (MySqlCommand command = new MySqlCommand(@"DROP TABLE IF EXISTS `data`;
CREATE TABLE `data` (
    `id` binary(16) NOT NULL,
    `group` binary(16),
    `data` blob NOT NULL,
    PRIMARY KEY (`id`),
    FOREIGN KEY (`group`) REFERENCES `data`(`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB;", tempConnection)) {
                    command.ExecuteNonQuery();
                }
            }
        }

        public string TestConnection(string host, string username, string password, string database) {
            using (MySqlConnection tempConnection = CreateConnection(host, username, password, database)) {
                tempConnection.Open();
                using (MySqlCommand command = new MySqlCommand("SELECT VERSION()", tempConnection)) {
                    return (string)command.ExecuteScalar();
                }
            }
        }
    }
}