PHP Unconference Europe 2015

PDO::query

(PHP 5 >= 5.1.0, PECL pdo >= 0.2.0)

PDO::query Executes an SQL statement, returning a result set as a PDOStatement object

Beschreibung

public PDOStatement PDO::query ( string $statement )
public PDOStatement PDO::query ( string $statement , int $PDO::FETCH_COLUMN , int $colno )
public PDOStatement PDO::query ( string $statement , int $PDO::FETCH_CLASS , string $classname , array $ctorargs )
public PDOStatement PDO::query ( string $statement , int $PDO::FETCH_INTO , object $object )

PDO::query() executes an SQL statement in a single function call, returning the result set (if any) returned by the statement as a PDOStatement object.

For a query that you need to issue multiple times, you will realize better performance if you prepare a PDOStatement object using PDO::prepare() and issue the statement with multiple calls to PDOStatement::execute().

If you do not fetch all of the data in a result set before issuing your next call to PDO::query(), your call may fail. Call PDOStatement::closeCursor() to release the database resources associated with the PDOStatement object before issuing your next call to PDO::query().

Hinweis:

Although this function is only documented as having a single parameter, you may pass additional arguments to this function. They will be treated as though you called PDOStatement::setFetchMode() on the resultant statement object.

Parameter-Liste

statement

The SQL statement to prepare and execute.

Data inside the query should be properly escaped.

R├╝ckgabewerte

PDO::query() returns a PDOStatement object, or FALSE on failure.

Beispiele

Beispiel #1 Demonstrate PDO::query

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

<?php
function getFruit($conn) {
    
$sql 'SELECT name, color, calories FROM fruit ORDER BY name';
    foreach (
$conn->query($sql) as $row) {
        print 
$row['name'] . "\t";
        print 
$row['color'] . "\t";
        print 
$row['calories'] . "\n";
    }
}
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

apple   red     150
banana  yellow  250
kiwi    brown   75
lemon   yellow  25
orange  orange  300
pear    green   150
watermelon      pink    90

Siehe auch

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User Contributed Notes 9 notes

up
8
fredrik at NOSPAM dot rambris dot com
7 years ago
The handling of errors by this function is controlled by the attribute PDO::ATTR_ERRMODE.

Use the following to make it throw an exception:
<?php
$dbh
->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
?>
up
2
dozoyousan at gmail dot com
8 years ago
> When query() fails, the boolean false is returned.

I think that is "Silent Mode".
If that set attribute ErrorMode "Exception Mode"
then that throw PDOException.
$pdoObj = new PDO( $dsn, $user, $pass );
$pdoObj->setAttribute("PDO::ATTR_ERRMODE", PDO::ERRMODE_EXCEPTION);
up
3
jonmsawyer at gmail dot com
7 years ago
@ dozoyousan at gmail dot com
> 03-May-2006 05:26
> > When query() fails, the boolean false is returned.
>
> I think that is "Silent Mode".
> If that set attribute ErrorMode "Exception Mode"
> then that throw PDOException.
> $pdoObj = new PDO( $dsn, $user, $pass );
> $pdoObj->setAttribute("PDO::ATTR_ERRMODE",
> PDO::ERRMODE_EXCEPTION);

What you say is correct, however, your PHP code is incorrect:

<?php
   
// This is fine
   
$pdoObj = new PDO( $dsn, $user, $pass );
   
   
// This line is wrong
   
$pdoObj->setAttribute("PDO::ATTR_ERRMODE", PDO::ERRMODE_EXCEPTION);
   
   
// It should be:
   
$pdoObj->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
   
   
// Parameter 1 should not be in quotes. PHP interprets
    // that as a string. Instead, internally, its represented
    // as type LONG INT. Try it :)
?>

Hope this helps. Cheers.
up
3
nicobn at gmail dot com
7 years ago
Please note that when Query() fails, it does not return a PDOStatement object . It simply returns false.
up
2
marcos at marcosregis dot com
6 years ago
After a lot of hours working with DataLink on Oracle->MySQL and PDO we (me and Adriano Rodrigues, that solve it) discover that PDO (and oci too) need the attribute AUTOCOMMIT set to FALSE to work correctly with.
There's  3 ways to set autocommit to false: On constructor, setting the atribute after construct and before query data or initiating a Transaction (that turns off autocommit mode)

The examples:
<?php
// First way - On PDO Constructor
$options = array(PDO::ATTR_AUTOCOMMIT=>FALSE);

$pdo = new PDO($dsn,$user,$pass,$options);

// now we are ready to query DataLinks

?>

<?php
// Second Way - Before create statements
$pdo = new PDO($dsn,$user,$pass);

$pdo->setAttribute(PDO::ATTR_AUTOCOMMIT,FALSE);
// or
$pdo->beginTransaction();

// now we are ready to query DataLinks
?>

To use DataLinks on oci just use OCI_DEFAULT on oci_execute() function;
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1
paolo at dellunto dot net
1 year ago
If you are using PDO to create an SQLite dbfile that will be used by an Android application, you can set common values via the $dbh->query("PRAGMA ...") statement;

a tipical example would be the user_version of the database or the page_size
<?php
...
$dbh = new PDO($PDO_DSN, null, null, null);
$dbh->query("PRAGMA page_size = 4096"); //Android match page size
$dbh->query("PRAGMA user_version = 2"); //This match super(context, DB_NAME, null, DB_VERSION) of the DatabaseOpenHelper
....
?>
up
1
stefano[dot]bertoli [at] gmail[dot]com
1 month ago
Trying to pass like second argument PDO::FETCH_ASSOC it still work.

So passing FETCH TYPE like argument seems work.

This save you from something like:

<?php
$result
= $stmt->setFetchMode(PDO::FETCH_NUM);
?>

Example:
<?php
$res
= $db->query('SELECT * FROM `mytable` WHERE true', PDO::FETCH_ASSOC);

?>
up
-2
andrea at bhweb dot it
6 years ago
If someone is suffering of the "MySQL server has gone away" problem after executing multiple queries, this is a solution that solved it for me. It's similar to the one needed for the exact same problem in mysqli.

<?php
$stmt
=$db->prepare($query);
$stmt->execute();
do {
$stmt->fetch(); $stmt->closeCursor(); ++$line; } while($stmt-
>
nextRowset());
?>

I found this only works using prepare and execute this way, not if you
directly execute the query with query().
up
-9
NUNTIUS
6 years ago
I found this method extremely useful for getting the iteration count. Note the usage of "for" instead of "while" or "foreach". Just place the "$row = $query->fetch()" as the second condition of your for loop (which is do until). This is the best of both worlds IMHO. Criticism welcome.

try {
    $hostname = "servername";
    $dbname = "dbname";
    $username = "username";
    $pw = "password";
    $pdo = new PDO ("mssql:host=$hostname;dbname=$dbname","$username","$pw");
  } catch (PDOException $e) {
    echo "Failed to get DB handle: " . $e->getMessage() . "\n";
    exit;
  }
      $query = $pdo->prepare("select name FROM tbl_name");
      $query->execute();
     
      for($i=0; $row = $query->fetch(); $i++){
        echo $i." - ".$row['name']."<br/>";
      }

      unset($pdo);
      unset($query);
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