c# 连接Mysql数据库

mysql.data.dll下载_c#连接mysql必要插件

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:WINNTSystem32 64位系统为C:WindowsSysWOW64
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, 3306);



 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(0) );

 }

 }

 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(0) );

 }

 }

 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();

 }