c# 连接Mysql数据库
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, 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();
}
