下拉菜单联动数据库

private void DropDownList_input(string input)
  {
    string connstring="Data Source=;user=;password=;";
   //实例化OracleConnection对象
   OracleConnection conn=new OracleConnection(connstring);
   //DropDownList2.DataSource=BindTheTitle();
   OracleDataAdapter da=new OracleDataAdapter("select column_name from user_tab_columns where table_name='"+input+"'",conn);

   DataSet ds=new DataSet();

   da.Fill(ds,"user_tab_columns");

   DropDownList2.DataSource=ds;

   DropDownList2.DataTextField="column_name";

   DropDownList2.DataValueField="column_name";

   DropDownList2.DataBind();
  }