c# 连接Mysql数据库

mysql.data.dll下载_c#连接mysql必要插件

全部版本下载：http://hovertree.com/h/bjaf/0sft36s9.htm

mysql.data.dll是C#操作MYSQL的驱动文件，是c#连接mysql必要插件，使c#语言更简洁的操作mysql数据库。当你的电脑弹出提示“丢失mysql.data.dll”或“无法找到mysql.data.dll”等错误问题，请下载本站为你提供的dll文件，使用它可以帮助用户解决上述问题。
dll文件修复方法：
1、解压下载的文件。
2、复制文件“mysql.data.dll”到系统目录下。
3、系统目录一般为：C:\WINNT\System32 64位系统为C:\Windows\SysWOW64
4、最后点击开始菜单-->运行-->输入regsvr32 mysql.data.dll 后，回车即可解决错误提示！

第三方组件：Mysql.Data.dll
说明：下载Mysql.Data.dll，然后在项目中添加该组件的引用，在代码页里输入using Mysql.Data.MysqlClient，我们就可以顺利的使用该类库的函数建立连接了。

以下是几个常用函数：

 #region  建立MySql数据库连接
     /// <summary>
     /// 建立数据库连接.
     /// </summary>
     /// <returns>返回MySqlConnection对象</returns>
     public MySqlConnection getmysqlcon()
     {
     //http://sosoft.cnblogs.com/
         string M_str_sqlcon = "server=localhost;user id=root;password=root;database=abc"; //根据自己的设置
         MySqlConnection myCon = new MySqlConnection(M_str_sqlcon);
         return myCon;
     }
     #endregion

     #region  执行MySqlCommand命令
     /// <summary>
     /// 执行MySqlCommand
     /// </summary>
     /// <param name="M_str_sqlstr">SQL语句</param>
     public void getmysqlcom(string M_str_sqlstr)
     {
         MySqlConnection mysqlcon = this.getmysqlcon();
         mysqlcon.Open();
         MySqlCommand mysqlcom = new MySqlCommand(M_str_sqlstr, mysqlcon);
         mysqlcom.ExecuteNonQuery();
         mysqlcom.Dispose();
         mysqlcon.Close();
         mysqlcon.Dispose();
     }
     #endregion

 #region  创建MySqlDataReader对象
     /// <summary>
     /// 创建一个MySqlDataReader对象
     /// </summary>
     /// <param name="M_str_sqlstr">SQL语句</param>
     /// <returns>返回MySqlDataReader对象</returns>
     public MySqlDataReader getmysqlread(string M_str_sqlstr)
     {
         MySqlConnection mysqlcon = this.getmysqlcon();
         MySqlCommand mysqlcom = new MySqlCommand(M_str_sqlstr, mysqlcon);
         mysqlcon.Open();
         MySqlDataReader mysqlread = mysqlcom.ExecuteReader(CommandBehavior.CloseConnection);
         return mysqlread;
     }
     #endregion

 using System.Data;

 using MySql.Data.MySqlClient;

 private MySqlConnection conn;

 private DataTable data;

 private MySqlDataAdapter da;

 private MySqlCommandBuilder  cb;

 private DataGrid  dataGrid;

 private void connectBtn_Click(object sender, System.EventArgs e)

  {

  if (conn != null)

  conn.Close();

  string connStr = String.Format("server={0};user id={1}; password={2}; port={3}; database=mysql; pooling=false; charset=utf8",

  server.Text, userid.Text, password.Text, );

  try 

  {

  conn = new MySqlConnection( connStr );

  conn.Open();

  GetDatabases();

                 MessageBox.Show("连接数据库成功!");

  }

  catch (MySqlException ex) 

  {

  MessageBox.Show( "Error connecting to the server: " + ex.Message );

  }

  }

  private void GetDatabases() 

  {

  MySqlDataReader reader = null;

  MySqlCommand cmd = new MySqlCommand("SHOW DATABASES", conn);

  try 

  {

  reader = cmd.ExecuteReader();

  databaseList.Items.Clear();

  while (reader.Read()) 

  {

  databaseList.Items.Add( reader.GetString() );

  }

  }

  catch (MySqlException ex) 

  {

  MessageBox.Show("Failed to populate database list: " + ex.Message );

  }

  finally 

  {

  if (reader != null) reader.Close();

  }

  }

  private void databaseList_SelectedIndexChanged(object sender, System.EventArgs e)

  {

  MySqlDataReader reader = null;

  conn.ChangeDatabase(databaseList.SelectedItem.ToString());

 //http://sosoft.cnblogs.com/

  MySqlCommand cmd = new MySqlCommand("SHOW TABLES", conn);

  try 

  {

  reader = cmd.ExecuteReader();

  tables.Items.Clear();

  while (reader.Read()) 

  {

  tables.Items.Add( reader.GetString() );

  }

  }

  catch (MySqlException ex) 

  {

  MessageBox.Show("Failed to populate table list: " + ex.Message );

  }

  finally 

  {

  if (reader != null) reader.Close();

  }

  }

  private void tables_SelectedIndexChanged(object sender, System.EventArgs e)

  {

  data = new DataTable();

  da = new MySqlDataAdapter("SELECT * FROM " + tables.SelectedItem.ToString(), conn );

      cb = new MySqlCommandBuilder( da ); // 此处必须有，否则无法更新

  da.Fill( data );

  dataGrid.DataSource = data;

  }

  private void updateBtn_Click(object sender, System.EventArgs e)

  {

  DataTable changes = data.GetChanges();

  da.Update( changes );

  data.AcceptChanges();

  }

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