Question

我使用此代码在我的网页上收到这些错误

Notice: Undefined variable: dbh in /home/danu2_cj3/public_html/lists.php on line 14

Fatal error: Call to a member function prepare() on a non-object in /home/danu2_cj3/public_html/lists.php on line 14

这是我正在使用的php代码，第14行是此代码中的第4行

<?php
/* Execute a prepared statement by binding PHP variables */
$member = $_SESSION['SESS_MEMBER_ID'];
$sth = $dbh->prepare('SELECT name
    FROM lists
    WHERE member_id = :member_id ');
$sth->bindValue(':member_id', $member, PDO::PARAM_INT);
$sth->execute();
?>

我正在尝试显示一堆行的数组，其中这些行中的一个字段应该与登录会话的人的member_id匹配

这里是页面的整个代码（top.php和bottom.php只是布局页面）

<?php include ('top.php')?>
<h1>My Profile </h1>
<a href="lists.php">My Lists</a> | <a href="logout.php">Logout</a></br>
</br>
Please select list to view/delete
<?php include ("connect.php")?>
<?php
/* Execute a prepared statement by binding PHP variables */
$member = $_SESSION['SESS_MEMBER_ID'];
$sth = $dbh->prepare('SELECT name
    FROM lists
    WHERE member_id = :member_id ');
$sth->bindValue(':member_id', $member, PDO::PARAM_INT);
$sth->execute();
?>

<?php include ('bottom.php')?>

这是我的connect.php文件

<?php
$username = "mydb";
$password = "mydb";
$hostname = "host"; 

//connection to the database
$dbh = mysql_connect($hostname, $username, $password) 
 or die("Unable to connect to database");

//select a database to work with
$selected = mysql_select_db("mydb",$dbh) 
  or die("Could not select database");
?>

Answer 1

您应该将connection添加到数据库或检查它是否在connect.php中正确设置

try 
{
    $dbh = new PDO($dsn, $user, $password);
} 
catch (PDOException $e) 
{
    echo 'Connection failed: ' . $e->getMessage();
}

DOCUMENTATION HERE

使用mySQL在PHP中使用命名占位符的预准备语句出错

1 个答案: