C#链接数据库、操作sql、选择串口

// 公共增删方法 

using MySql.Data.MySqlClient;
using System.Data;    namespace ******
{public class MySQLHelper{private MySqlConnection conn = null;private MySqlCommand comm = null;private MySqlDataReader reader = null;/// <summary>/// 构造方法里建议连接/// </summary>/// <param name="connStr"></param>public MySQLHelper(string connStr){conn = new MySqlConnection(connStr);}/// <summary>/// 发送指令/// </summary>/// <param name="sql"></param>public void CreateCommand(string sql){if (conn.State == ConnectionState.Closed){conn.Open();}comm = new MySqlCommand(sql, conn);}/// <summary>/// 增删改公共方法/// </summary>/// <returns></returns>public int commonExecute(){int res;res = comm.ExecuteNonQuery();conn.Close();return res;}/// <summary>/// 查询方法/// </summary>/// <returns></returns>public DataTable selectExecute(){DataTable dt = new DataTable();using (reader = comm.ExecuteReader(CommandBehavior.CloseConnection)){dt.Load(reader);}return dt;}}
}

//   代码中引用

using Sunny.UI;
using System.Threading;
using System.IO.Ports;
using System;
using System.Data;string connStr = "Database=db_oxygen_check;Data Source=127.0.0.1;User Id=root;Password=root;pooling=false;CharSet=utf8;port=3306;";private void SystemSettingForm_Load(object sender, EventArgs e){//  获取可用串口、将串口名称回显到页面上string[] portNames = SerialPort.GetPortNames();foreach (string portName in portNames){uiComboBox2.Items.Add(portName);}if (uiComboBox2.Items.Count > 0){uiComboBox2.SelectedIndex = 0;MySQLHelper mySQLHelper = new MySQLHelper(connStr);string sql = "select * from tb_system_settings";mySQLHelper.CreateCommand(sql);DataTable dataTable = mySQLHelper.selectExecute();if (dataTable.Rows.Count > 0){txt_plcCom.Text = dataTable.Rows[0]["plc_com"].ToString();uiComboBox2.Text = dataTable.Rows[0]["oxygen_com"].ToString();}}}

//  按钮选中串口号和地址

      private void uiButton1_Click(object sender, EventArgs e){string plcCom = txt_plcCom.Text;string oxygenCom = uiComboBox2.Text;if (plcCom.Trim().Length == 0){UIMessageBox.ShowError("请选择正确的PLC IP地址");return;}if (oxygenCom.Trim().Length == 0){UIMessageBox.ShowError("请选择正确的***串口号");return;}string sql = "update tb_system_settings set plc_com = '" + plcCom + "', oxygen_com = '" + oxygenCom + "' where id = 1";MySQLHelper mySQLHelper = new MySQLHelper(connStr);mySQLHelper.CreateCommand(sql);int res = mySQLHelper.commonExecute();if (res > 0){UIMessageBox.ShowSuccess("设置成功！");DialogResult = System.Windows.Forms.DialogResult.OK;Thread thread = new Thread(new ParameterizedThreadStart(logWrite));OperateLog op = new OperateLog();op.operateType = 2;op.adminId = LoginDataStatic.id;op.adminName = LoginDataStatic.name;op.operageDesc = "修改系统设定为：{PLC串口号: " + plcCom + ", ***串口号: " + oxygenCom + "}";op.createTime = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");thread.Start(op);}else{UIMessageBox.ShowError("设置失败！");DialogResult = System.Windows.Forms.DialogResult.Cancel;}}