Last updated: Fri, 14 Aug 2009

PDOStatement->rowCount

(PHP 5 >= 5.1.0, PECL pdo >= 0.1.0)

PDOStatement->rowCount — Retourne le nombre de lignes affectées par le dernier appel à la fonction PDOStatement::execute()

Description

int PDOStatement::rowCount ( void )

PDOStatement::rowCount() retourne le nombre de lignes affectées par la dernière requête DELETE, INSERT ou UPDATE exécutée par l'objet PDOStatement correspondant.

Si la dernière requête SQL exécutée par l'objet PDOStatement associé est une requête de type SELECT, quelques bases de données retourneront le nombre de lignes retournées par cette requête. Néanmoins, ce comportement n'est pas garanti pour toutes les bases de données et ne devrait pas être exécuté pour des applications portables.

Valeurs de retour

Retourne le nombre de lignes.

Exemples

Exemple #1 Retourne le nombre de lignes effacées

PDOStatement::rowCount() retourne le nombre de lignes affectées par une requête DELETE, INSERT, ou UPDATE.


<?php
/* Effacement de toutes les lignes de la table FRUIT */
$del = $dbh->prepare('DELETE FROM fruit');
$del->execute();

/* Retourne le nombre de lignes effacées */
print("Retourne le nombre de lignes effacées :\n");
$count = $del->rowCount();
print("Effacement de $count lignes.\n");
?>

L'exemple ci-dessus va afficher :

Effacement de 9 lignes.

Exemple #2 Comptage des lignes retournées par une requête SELECT

Pour la plupart des bases de données, PDOStatement::rowCount() ne retourne pas le nombre de lignes affectées par une requête SELECT. À la place, utilisez PDO::query() pour faire une requête SELECT COUNT(*), puis utilisez PDOStatement::fetchColumn() pour récupérer le nombre de lignes retournées. Votre application peut ainsi effectuer la bonne action.


<?php
$sql = "SELECT COUNT(*) FROM fruit WHERE calories > 100";
if ($res = $conn->query($sql)) {

   /* Récupère le nombre de lignes qui correspond à la requête SELECT */
   if ($res->fetchColumn() > 0) {

      /* Effectue la vraie requête SELECT et travaille sur le résultat */
      $sql = "SELECT nom FROM fruit WHERE calories > 100";
      foreach ($conn->query($sql) as $row) {
      print "Nom : " .  $row['NOM'] . "\n";
      }
   }
   /* Aucune ligne ne correspond -- faire quelque chose d'autre */
   else {
      print "Aucune ligne ne correspond à la requête.";
   }
}

$res = null;
$conn = null;
?>

L'exemple ci-dessus va afficher :

apple
banana
orange
pear

Voir aussi

PDOStatement::columnCount() - Retourne le nombre de colonnes dans le jeu de résultats
PDOStatement::fetchColumn() - Retourne une colonne depuis la ligne suivante d'un jeu de résultats
PDO::query() - Exécute une requête SQL, retourne un jeu de résultats en tant qu'objet PDOStatement

PDOStatement->setAttribute

PDOStatement->nextRowset

Last updated: Fri, 14 Aug 2009

add a note User Contributed Notes
PDOStatement->rowCount

php at alishabeth dot com
21-Jan-2009 01:15


It appears that rowCount behavior is different on Mysql 5.0 vs 5.1.  Here's the test I ran:



<?php

$db = new PDO('mysql:host=localhost;dbname=test','test','test');

$sql = "SELECT 1";

$st = $db->prepare($sql);

$st->execute();

print_r($st->rowCount());

?>



Mysql 5.0.45, PHP 5.2.5 returned 1



Mysql 5.1.30, PHP 5.1.6 returned 0



I know... I need to test against same php versions... buy I'm getting lazy...

e dot sand at elisand dot com
19-Nov-2008 07:32


My rowCount() workaround & how it's used:



<?php

class MyPDO extends PDO {

    private $queryString;



    public function query(/* ... */) {

        $args = func_get_args();

        $this->queryString = func_get_arg(0);



        return call_user_func_array(array(&$this, 'parent::query'), $args);

    }



    public function rowCount() {

        $regex = '/^SELECT\s+(?:ALL\s+|DISTINCT\s+)?(?:.*?)\s+FROM\s+(.*)$/i';

        if (preg_match($regex, $this->queryString, $output) > 0) {

            $stmt = parent::query("SELECT COUNT(*) FROM {$output[1]}", PDO::FETCH_NUM);



            return $stmt->fetchColumn();

        }



        return false;

    }

}



$pdo = new MyPDO("sqlite::memory:");

$result = $pdo->query("SELECT row1, row2 FROM table WHERE something = 5");



if ($pdo->rowCount() > 0) {

    echo "{$result['row1']}, {$result['row2']}";

}

?>

e dot sand at elisand dot com
19-Nov-2008 07:30


As of SQLite 3.x, the SQLite API itself changed and now all queries are implemented using "statements".  Because of this, there is no way for PDO to know the rowCount of a SELECT result because the SQLite API itself doesn't offer this ability.



As a workaround, I created my own rowCount() function - it's a bit of a hack and hasn't been fully tested yet (I don't know how it will work when using JOINs in SELECTs, etc...), but at least alleviates the necessity for SELECT COUNT(*)'s everywhere in your code.



I would have preferred if it were possible to overload the rowCount() function from PDOStatement, but I don't think it's possible (or I don't know how to do it).  There's also potential room for a bit more security ensuring that $queryString is wiped clean after other query()s so that you don't get a bad result, etc...



The actual code should be posted in the above/below post (max post limits, argh!).  If others wish to extend/perfect this method, please keep me posted with an email as to what you've done.

gunnrosebutpeace at gmail dot com
03-Jun-2008 10:19


It'd better to use SQL_CALC_FOUND_ROWS, if you only use MySQL. It has many advantages as you could retrieve only part of result set (via LIMIT) but still get the total row count.


code:


<?php


$db = new PDO(DSN...);


$db->setAttribute(array(PDO::MYSQL_USE_BUFFERED_QUERY=>TRUE));


$rs  = $db->query('SELECT SQL_CALC_FOUND_ROWS * FROM table LIMIT 5,15');


$rs1 = $db->query('SELECT FOUND_ROWS()');


$rowCount = (int) $rs1->fetchColumn();


?>

Anonymous
26-Dec-2007 12:10


The rowCount method does not seem to work with pdo_sqlite, maybe because it will not support forward-only cursors:



<?php

error_reporting(E_ALL+E_NOTICE);



$dsn = 'sqlite::memory:';

$pdo = new PDO($dsn);



$pdo->exec('CREATE TABLE foo(id varchar(11) NOT NULL, PRIMARY KEY(id))');

$pdo->exec("INSERT INTO foo(id) VALUES ('ffs')");



$sqlGet = 'SELECT * FROM foo WHERE id=:id';

$stmt = $pdo->prepare($sqlGet);

$id = 'ffs';

$stmt->bindParam(':id', $id, PDO::PARAM_STR);

$stmt->execute();



var_dump($stmt->rowCount(), count($stmt->fetchAll()));

?>



which outputs: 0 1



http://php.net/manual/en/function.sqlite-num-rows.php says sqlite_num_rows() cannot be used on unbuffered results; the explanation to the failure of the rowCount() method is probably along the same lines.

The workaround would be to use the count() function on a fetched result, but it might not be as efficient.

Mr. Perl
14-Nov-2007 03:06


To Matt,



PDO is very similar in design to Perl's DBI which does allow you to set driver specific attributes such as mysql_client_found_rows=1 as part of the DSN. 



PDO has a setAttribute() method, but afaik there is no 

MYSQL_ATTR_CLIENT_FOUND_ROWS constant (yet). Hopefully some PDO developer will patch it in one day.



Setting that (at least in Perl and C) will make rowCount() return the number of rows selected for the update, not just the number of rows actually updated.

Matt
07-Oct-2007 04:22


Great, while using MySQL5, the only way to get the number of rows after doing a PDO SELECT query is to either execute a separate SELECT COUNT(*) query (or to do count($stmt->fetchAll()), which seems like a ridiculous waste of overhead and programming time.



Another gripe I have about PDO is its inability to get the value of output parameters from stored procedures in some DBMSs, such as SQL Server.



I'm not so sure I'm diggin' PDO yet.

evangun2001 at yahoo dot fr
10-Sep-2007 05:59


hipska at mac dot com : what you say is not correct.

The resulting $fruits cannot be used as an array, and count($fruits) always equals 1.



The confusion is however understandable, since foreach ($fruits->query($query) as $row){} will work, as with any array.



The most efficient way to retrieve number of rows found by SELECT in a portable application is probably to make a condition :



- Check that the current database system (get its name via getAttribute()), is one where rowCount() returns the number of rows found

1) If it does, there you have it

2) If it does not, execute an extra COUNT query.

pcdinh at phpvietnam dot net
21-Mar-2006 10:39


In some case you need to know how many row are retrieved from a select query (i.e to page a result set) you can use:



$totalRows = count($resultSet->fetchAll());



It works on MySQL 5.0.18 and PHP 5.1

Pablo Godel
30-Jan-2006 08:18


For large resultsets the method described below is not very efficient. It is better to do a select COUNT(*).

add a note

PDOStatement->setAttribute

PDOStatement->nextRowset

Last updated: Fri, 14 Aug 2009