International PHP Conference 2015

PDOStatement::fetchObject

(PHP 5 >= 5.1.0, PECL pdo >= 0.2.4)

PDOStatement::fetchObjectFetches the next row and returns it as an object.

Beschreibung

public mixed PDOStatement::fetchObject ([ string $class_name = "stdClass" [, array $ctor_args ]] )

Fetches the next row and returns it as an object. This function is an alternative to PDOStatement::fetch() with PDO::FETCH_CLASS or PDO::FETCH_OBJ style.

Parameter-Liste

class_name

Name of the created class.

ctor_args

Elements of this array are passed to the constructor.

R├╝ckgabewerte

Returns an instance of the required class with property names that correspond to the column names Im Fehlerfall wird FALSE zur├╝ckgegeben..

Siehe auch

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User Contributed Notes 5 notes

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44
rasmus at mindplay dot dk
2 years ago
Be warned of the rather unorthodox behavior of PDOStatement::fetchObject() which injects property-values BEFORE invoking the constructor - in other words, if your class  initializes property-values to defaults in the constructor, you will be overwriting the values injected by fetchObject() !

A var_dump($this) in your __construct() method will reveal that property-values have been initialized prior to calling your constructor, so be careful.

For this reason, I strongly recommend hydrating your objects manually, after retrieving the data as an array, rather than trying to have PDO apply properties directly to your objects.

Clearly somebody thought they were being clever here - allowing you to access hydrated property-values from the constructor. Unfortunately, this is just not how OOP works - the constructor, by definition, is the first method called upon construction.

If you need to initialize your objects after they have been constructed and hydrated, I suggest your model types implement an interface with an init() method, and you data access layer invoke this method (if implemented) after hydrating.
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3
dave at davidhbrown dot us
2 months ago
If using a namespaced class, you must provide the fully qualified class name; fetchObject does not seem to know about any "use" statements.

This results in a PHP Fatal error: Class 'MyClass' not found...:
<?php
use MyNamespace\MyClass;
// ...
$o = $statement->fetchObject('MyClass'));
?>
This works:
<?php
use MyNamespace\MyClass; //still needed for my code
// ...
$o = $statement->fetchObject('MyNamespace\\MyClass'));
?>
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1
beinghavingbreackfast at gmail dot com
1 month ago
It should be mentioned that this method can set even non-public properties. It may sound strange but it can actually be very useful when creating an object based on mysql result.
Consider a User class:

<?php
class User {
  
// Private properties
  
private $id, $name;

   private function
__construct () {}

   public static function
load_by_id ($id) {
     
$stmt = $pdo->prepare('SELECT id, name FROM users WHERE id=?');
     
$stmt->execute([$id]);
      return
$stmt->fetchObject(__CLASS__);
   }
  
/* same method can be written with the "name" column/property */
}

$user = User::load_by_id(1);
var_dump($user);
?>

fetchObject() doesn't care about properties being public or not. It just passes the result to the object. Output is like:

object(User)#3 (2) {
  ["id":"User":private]=>
  string(1) "1"
  ["name":"User":private]=>
  string(10) "John Smith"
}
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-7
Anonymous
5 months ago
I think so could us use this variant to implement the constructor, this is my example:

<?php
class User{
    public
$user;
    public
$password;
    public
$name;
    public
$email;
   
    public function
__construct(){
       
$args = func_get_args();
       
$nargs = func_num_args();
       
$attribs = get_class_vars(get_class($this));
        if(isset(
$args)){
            foreach(
$args as $value){
               
$attrib = key($attribs);
               
$this->$attrib = $value;
               
next($attribs);
            }
        }
    }
}
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-18
Vegard Lkken
1 year ago
Because of the injection of object properties before the constructor is executed, I usually build my classes like this to make sure already set properties aren't overwritten:

<?php
class Person {
  public
$name;
  public
$age;
  public
$sex;

  public function
__construct($name=NULL, $age=NULL, $sex=NULL) {
   
$this->name = $name === NULL ? $this->name : $name;
   
$this->age = $age === NULL ? $this->age : $age;
   
$this->sex = $sex === NULL ? $this->sex : $sex;
  }
}
?>
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