using MySql.Data.MySqlClient;

.
.
.

            string myConnectionString = "Database=" + bazaDanych + ";Data Source=" + host + ";User Id=" + login + ";Password=" + pass + ";CharSet=" + kodowanie;
            MySqlConnection myConnection = new MySqlConnection(myConnectionString);
            try
            {
                string mySelectQuery = "SELECT * FROM tabela";
                MySqlCommand myCommand = new MySqlCommand(mySelectQuery);
                myCommand.Connection = myConnection;
                myConnection.Open();
                MySqlDataReader myReader;
                myReader = myCommand.ExecuteReader();
                string[] row = new string[5];
                i = 1;
                while (myReader.Read())
                {
                    row[0] = i.ToString();
                    row[1] = myReader.GetString(0);
                    row[2] = myReader.GetString(2);
                    row[3] = myReader.GetString(3);
                    row[4] = myReader.GetString(1);
                    naszDataGrid.Rows.Add(row);
                    i++;
                }
		myCommand.Connection.Close();

.
.
.

                MySqlConnection myConnection = new MySqlConnection(myConnectionString);
                try
                {
                    string myInsertQuery = "INSERT INTO `tabela` (nazwa) Values(?nazwa)";
                    MySqlCommand myCommand = new MySqlCommand(myInsertQuery);
                    myCommand.Connection = myConnection;
                    myConnection.Open();
                    myCommand.Parameters.AddWithValue("?nazwa", nazwa.Text);
                    myCommand.ExecuteNonQuery();
                    myCommand.Connection.Close();
                }
                catch (Exception ee)
                {
                    MessageBox.Show("Problem z połączeniem do bazy danych: " + ee.ToString());
                }
                finally
                {
                    myConnection.Close();
                    this.Close();
                }