将代码从 MySQL 更改为 PDO

我制作了一个使用 MySQL 语法编写的 CMS 脚本。

我想用 PDO 语法替换 MySQL 语法。有人可以吗帮我做 and 向我解释一下该怎么做?

这是脚本中的代码。

<?php
    $querytemp = mysql_query("select * from main_setting") or die (mysql_error());
    $row = mysql_fetch_object($querytemp);

    include "inc/upcenter_block.php";

    echo "
        <div class='headmenu'>$row->news1</div>
        <div class='bodymenu'>
        <p>".nl2br($row->news)."</p>
    </div> ";

    include "inc/downcenter_block.php";
?>

首先如果你想改变mysql_* to PDO

您将需要更改脚本中的所有代码，而不仅仅是 单一的就行不通

如果您要将代码从 mysql* 更改为 PDO

您必须使用 PDO 更改与数据库的连接

这是一个示例：

// here we set the variables 
$dbhost = "localhost";
$dbname = "testcreate";
$dbuser = "root";
$dbpass = "mysql";

// here we are using ( try {} ) to catch the errors that will shows up and handle it in a nicer way
    try {
    $db = new PDO('mysql:host='.$dbhost.';dbname='.$dbname.';charset=utf-8', ''.$dbuser.'', ''.$dbpass.'');
    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    } catch (PDOException $e) {
        echo 'Error : <br>' . $e->getMessage();
    }

// here we set the varible for the connection = then starting the cennction with new POD();
$db = new PDO('mysql:host='.$dbhost.';dbname='.$dbname.';charset=utf-8', ''.$dbuser.'', ''.$dbpass.'');

// here we set an Attribute to handle the errors
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
// you dont need to use it in our case because we already catching the error and handling it in out way

  // here we catch the error then handling it by echo a msg and then we used
  // $e->getMessage(); to get the error msg that should be throwing in the page
    catch (PDOException $e) {
        echo 'Error : <br>' . $e->getMessage();
    }

--------------------------------------------------------

现在我们已经完成了连接 我将向您展示如何查询和获取表

 // this is how we will use query
 $qr = $db->query()

 // and this is how to fetch it by taking the query variable and use the arrow then fetch 
 $ro = $qr->fetch()

我将向您展示一个代码示例

$querytemp = mysql_query("select * from main_setting") or die (mysql_error());
$row = mysql_fetch_object($querytemp);

我们将其更改为

$querytemp = $db->query("select * from main_setting");
$row = $querytemp->fetch(PDO::FETCH_OBJ);

所以现在你可以使用$row->news与 PDO

现在您可以轻松地将代码更改为 PDO