如何将此 mysqli 转换为 PDO?

How can I convert this mysqli to PDO?

<?php

    require_once('dbconfig.php');
    global $con;

    $query = $con->prepare("SELECT * FROM userinfo order by id DESC");
    $query->execute();
    mysqli_stmt_bind_result($query, $id, $name, $username, $password);

试试这个

$dsn = "mysql:host=localhost;dbname=myDatabase;charset=utf8mb4";
$options = [
  PDO::ATTR_EMULATE_PREPARES   => false, // turn off emulation mode for "real" prepared statements
  PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION, //turn on errors in the form of exceptions
  PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC, //make the default fetch be an associative array
];
try {
  $pdo = new PDO($dsn, "username", "password", $options);
} catch (Exception $e) {
  error_log($e->getMessage());
  exit('Something weird happened'); //something a user can understand
}

$arr = $pdo->query("SELECT * FROM myTable")->fetchAll(PDO::FETCH_ASSOC);

你应该使用 ->bindColumn Manual

另见 This answer

  • 最佳实践:不要使用 SELECT * 而是定义您需要从 table.
  • 中获取的每一列
  • 不要全球化你的连接变量。这是一个安全风险以及增加膨胀,你的代码应该不需要。
  • 因为它是一个静态语句,所以您可以使用 ->query 而不是 prepare,因为不需要准备任何东西。

解决方案:

$query = $con->query("SELECT id,name,username,password FROM userinfo ORDER BY id DESC");
try {
   $query->execute();
   $query->bindColumn(1, $id);
   $query->bindColumn(2, $name); 
   $query->bindColumn(3, $username); 
   $query->bindColumn(4, $password); 
}
catch (PDOException $ex) {
   error_log(print_r($ex,true);
}

或者:

A nice feature of PDO::query() is that it enables you to iterate over the rowset returned by a successfully executed SELECT statement. From the manual

foreach ($conn->query('SELECT id,name,username,password FROM userinfo ORDER BY id DESC') as $row) {
    print $row['id'] . " is the ID\n";
    print $row['name'] . " is the Name\n";
    print $row['username'] . " is the Username\n";
}

另请参阅:

对他们的回答有一些很好的提示,您应该使用他们的 $options 设置以及使用他们建议的 utf8mb4 连接字符集。

他们使用 ->fetchAll 的建议也完全有效。