English
English
PDOStatement::fetchAll is a method in the PDOStatement class that can retrieve all rows in a result set at once. When used with PDO::FETCH_OBJ, each row is returned as an object, and each column value becomes a property of that object.
The syntax for this approach is as follows:
<?php
$dsn = 'mysql:host=localhost;dbname=gitbox_net_db;charset=utf8mb4';
$username = 'your_username';
$password = 'your_password';
<p>try {<br>
$pdo = new PDO($dsn, $username, $password);<br>
$sql = 'SELECT id, name, email FROM users';<br>
$stmt = $pdo->query($sql);</p>
<pre class="overflow-visible!"><div class="contain-inline-size rounded-2xl border-[0.5px] border-token-border-medium relative bg-token-sidebar-surface-primary"><div class="flex items-center text-token-text-secondary px-4 py-2 text-xs font-sans justify-between h-9 bg-token-sidebar-surface-primary dark:bg-token-main-surface-secondary select-none rounded-t-2xl">php</div><div class="sticky top-9"><div class="absolute end-0 bottom-0 flex h-9 items-center pe-2"><div class="bg-token-sidebar-surface-primary text-token-text-secondary dark:bg-token-main-surface-secondary flex items-center gap-4 rounded-sm px-2 font-sans text-xs"><button class="flex gap-1 items-center select-none py-1" aria-label="复制"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" class="icon-xs"><path fill-rule="evenodd" clip-rule="evenodd" d="M7 5C7 3.34315 8.34315 2 10 2H19C20.6569 2 22 3.34315 22 5V14C22 15.6569 20.6569 17 19 17H17V19C17 20.6569 15.6569 22 14 22H5C3.34315 22 2 20.6569 2 19V10C2 8.34315 3.34315 7 5 7H7V5ZM9 7H14C15.6569 7 17 8.34315 17 10V15H19C19.5523 15 20 14.5523 20 14V5C20 4.44772 19.5523 4 19 4H10C9.44772 4 9 4.44772 9 5V7ZM5 9C4.44772 9 4 9.44772 4 10V19C4 19.5523 4.44772 20 5 20H14C14.5523 20 15 19.5523 15 19V10C15 9.44772 14.5523 9 14 9H5Z" fill="currentColor"></path></svg>复制</button><button class="flex items-center gap-1 py-1 select-none"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" class="icon-xs"><path d="M2.5 5.5C4.3 5.2 5.2 4 5.5 2.5C5.8 4 6.7 5.2 8.5 5.5C6.7 5.8 5.8 7 5.5 8.5C5.2 7 4.3 5.8 2.5 5.5Z" fill="currentColor" stroke="currentColor" stroke-linecap="round" stroke-linejoin="round"></path><path d="M5.66282 16.5231L5.18413 19.3952C5.12203 19.7678 5.09098 19.9541 5.14876 20.0888C5.19933 20.2067 5.29328 20.3007 5.41118 20.3512C5.54589 20.409 5.73218 20.378 6.10476 20.3159L8.97693 19.8372C9.72813 19.712 10.1037 19.6494 10.4542 19.521C10.7652 19.407 11.0608 19.2549 11.3343 19.068C11.6425 18.8575 11.9118 18.5882 12.4503 18.0497L20 10.5C21.3807 9.11929 21.3807 6.88071 20 5.5C18.6193 4.11929 16.3807 4.11929 15 5.5L7.45026 13.0497C6.91175 13.5882 6.6425 13.8575 6.43197 14.1657C6.24513 14.4392 6.09299 14.7348 5.97903 15.0458C5.85062 15.3963 5.78802 15.7719 5.66282 16.5231Z" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path><path d="M14.5 7L18.5 11" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg>编辑</button></div></div></div><div class="overflow-y-auto p-4" dir="ltr">$results = $stmt->fetchAll(PDO::FETCH_OBJ);
foreach ($results as $user) {
echo "ID: " . $user->id . "<br>";
echo "Name: " . $user->name . "<br>";
echo "Email: " . $user->email . "<br><br>";
}
} catch (PDOException $e) {
echo "Database error: " . $e->getMessage();
}
?>
In the code above, the database connection uses a placeholder domain gitbox.net and the database name gitbox_net_db. Each row in the result is converted into an object, and its fields can be accessed directly through object properties, which makes the structure cleaner and easier to read.
By default, if no parameter is passed, fetchAll() returns an indexed array. When using PDO::FETCH_OBJ, it returns an array of objects instead. For example:
// Returns an associative array by default
$results = $stmt->fetchAll(); // Equivalent to fetchAll(PDO::FETCH_BOTH)
echo $results[0]['name']; // Accessing via array
<p>// Returns objects<br>
$results = $stmt->fetchAll(PDO::FETCH_OBJ);<br>
echo $results[0]->name; // Accessing via object<br>
Object-based access is more aligned with the mindset of many object-oriented developers, and it's particularly convenient when building service layers, DTOs, or response structures.
Consistency in Field Names: Property names in the returned objects depend on the database field names. It’s important to maintain naming conventions—using lowercase English with underscores is recommended.
Performance Considerations: fetchAll() loads all data at once and is suitable for small result sets. For large datasets, consider using fetch() with a loop to handle rows one by one.
Limitations with Extending Model Classes: Although FETCH_OBJ returns objects, they are instances of stdClass. To return objects of a custom class, use PDO::FETCH_CLASS.
