How to write dedecms: add, delete, modify, check

<?php
      require_once (dirname(__FILE__) . "/include/common.inc.php");  //引用数据库连接文件
      if($dsql->IsTable(&#39;dede_test&#39;)){
          //如果存在dede_test表
          //-------------------
          //|    查询一条记录 |
          //|    GetOne()     |
          //-------------------
          //        ↓
          $row = $dsql->GetOne("SELECT * FROM dede_test WHERE id = 3");
          print_r($row);
         $sql = "SELECT * FROM dede_test";
            $dsql->Execute(&#39;me&#39;,$sql);
            while($arr = $dsql->GetArray(&#39;me&#39;))
            {
                echo "id = {$arr[&#39;id&#39;]} ,name = {$arr[&#39;name&#39;]}<br />";
            }
      }
?>

<?php
            $id = 1 ;
            if($id>0){
                $sql = "DELETE FROM dede_test WHERE id=&#39;$id&#39;";
                $dsql->ExecuteNoneQuery($sql);
                ShowMsg("成功删除一条记录内容！","true.php");  //执行成功后跳转到true.php页面
                exit();  
            }else{
                 ShowMsg("参数不对！","text.php");  //跳转到text.php页面
                exit();  
            }
?>

<?php
       $sql="INSERT INTO dede_test(name,one,two) VALUES ( &#39;$name&#39;,&#39;$one&#39;,&#39;$two&#39;)";
            $dsql->ExecuteNoneQuery($sql);
            $lastInsertID = $dsql->GetLastID();
            ShowMsg("成功增加一条记录内容！","test.php");
?>

<?php
            $sql="UPDATE dede_test SET name=&#39;$name&#39;,one=&#39;$one&#39;,two=&#39;$two&#39;  WHERE ID = &#39;$id&#39;";
            $dsql->ExecuteNoneQuery($sql);
            $lastInsertID = $dsql->GetLastID();
            ShowMsg("成功修改一条记录内容！","true.php");  //操作成功跳转到true.php
            exit();

?>