Last updated: Fri, 06 Nov 2009

PDOStatement->fetch

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

PDOStatement->fetch — Fetches the next row from a result set

Description

mixed PDOStatement::fetch ([ int $fetch_style = PDO::FETCH_BOTH [, int $cursor_orientation = PDO::FETCH_ORI_NEXT [, int $cursor_offset = 0 ]]] )

Fetches a row from a result set associated with a PDOStatement object. The fetch_style parameter determines how PDO returns the row.

Parameters

fetch_style

Controls how the next row will be returned to the caller. This value must be one of the PDO::FETCH_* constants, defaulting to PDO::FETCH_BOTH.

PDO::FETCH_ASSOC: returns an array indexed by column name as returned in your result set
PDO::FETCH_BOTH (default): returns an array indexed by both column name and 0-indexed column number as returned in your result set
PDO::FETCH_BOUND: returns TRUE and assigns the values of the columns in your result set to the PHP variables to which they were bound with the PDOStatement::bindColumn() method
PDO::FETCH_CLASS: returns a new instance of the requested class, mapping the columns of the result set to named properties in the class. If fetch_style includes PDO::FETCH_CLASSTYPE (e.g. PDO::FETCH_CLASS | PDO::FETCH_CLASSTYPE) then the name of the class is determined from a value of the first column.
PDO::FETCH_INTO: updates an existing instance of the requested class, mapping the columns of the result set to named properties in the class
PDO::FETCH_LAZY: combines PDO::FETCH_BOTH and PDO::FETCH_OBJ, creating the object variable names as they are accessed
PDO::FETCH_NUM: returns an array indexed by column number as returned in your result set, starting at column 0
PDO::FETCH_OBJ: returns an anonymous object with property names that correspond to the column names returned in your result set

cursor_orientation

For a PDOStatement object representing a scrollable cursor, this value determines which row will be returned to the caller. This value must be one of the PDO::FETCH_ORI_* constants, defaulting to PDO::FETCH_ORI_NEXT. To request a scrollable cursor for your PDOStatement object, you must set the PDO::ATTR_CURSOR attribute to PDO::CURSOR_SCROLL when you prepare the SQL statement with PDO::prepare().

offset

For a PDOStatement object representing a scrollable cursor for which the cursor_orientation parameter is set to PDO::FETCH_ORI_ABS, this value specifies the absolute number of the row in the result set that shall be fetched.

For a PDOStatement object representing a scrollable cursor for which the cursor_orientation parameter is set to PDO::FETCH_ORI_REL, this value specifies the row to fetch relative to the cursor position before PDOStatement::fetch() was called.

Return Values

The return value of this function on success depends on the fetch type. In all cases, FALSE is returned on failure.

Examples

Example #1 Fetching rows using different fetch styles


<?php
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();

/* Exercise PDOStatement::fetch styles */
print("PDO::FETCH_ASSOC: ");
print("Return next row as an array indexed by column name\n");
$result = $sth->fetch(PDO::FETCH_ASSOC);
print_r($result);
print("\n");

print("PDO::FETCH_BOTH: ");
print("Return next row as an array indexed by both column name and number\n");
$result = $sth->fetch(PDO::FETCH_BOTH);
print_r($result);
print("\n");

print("PDO::FETCH_LAZY: ");
print("Return next row as an anonymous object with column names as properties\n");
$result = $sth->fetch(PDO::FETCH_LAZY);
print_r($result);
print("\n");

print("PDO::FETCH_OBJ: ");
print("Return next row as an anonymous object with column names as properties\n");
$result = $sth->fetch(PDO::FETCH_OBJ);
print $result->NAME;
print("\n");
?>

The above example will output:

PDO::FETCH_ASSOC: Return next row as an array indexed by column name
Array
(
    [NAME] => apple
    [COLOUR] => red
)

PDO::FETCH_BOTH: Return next row as an array indexed by both column name and number
Array
(
    [NAME] => banana
    [0] => banana
    [COLOUR] => yellow
    [1] => yellow
)

PDO::FETCH_LAZY: Return next row as an anonymous object with column names as properties
PDORow Object
(
    [NAME] => orange
    [COLOUR] => orange
)

PDO::FETCH_OBJ: Return next row as an anonymous object with column names as properties
kiwi

Example #2 Fetching rows with a scrollable cursor


<?php
function readDataForwards($dbh) {
  $sql = 'SELECT hand, won, bet FROM mynumbers ORDER BY BET';
  try {
    $stmt = $dbh->prepare($sql, array(PDO::ATTR_CURSOR => PDO::CURSOR_SCROLL));
    $stmt->execute();
    while ($row = $stmt->fetch(PDO::FETCH_NUM, PDO::FETCH_ORI_NEXT)) {
      $data = $row[0] . "\t" . $row[1] . "\t" . $row[2] . "\n";
      print $data;
    }
    $stmt = null;
  }
  catch (PDOException $e) {
    print $e->getMessage();
  }
}
function readDataBackwards($dbh) {
  $sql = 'SELECT hand, won, bet FROM mynumbers ORDER BY bet';
  try {
    $stmt = $dbh->prepare($sql, array(PDO::ATTR_CURSOR => PDO::CURSOR_SCROLL));
    $stmt->execute();
    $row = $stmt->fetch(PDO::FETCH_NUM, PDO::FETCH_ORI_LAST);
    do {
      $data = $row[0] . "\t" . $row[1] . "\t" . $row[2] . "\n";
      print $data;
    } while ($row = $stmt->fetch(PDO::FETCH_NUM, PDO::FETCH_ORI_PRIOR));
    $stmt = null;
  }
  catch (PDOException $e) {
    print $e->getMessage();
  }
}

print "Reading forwards:\n";
readDataForwards($conn);

print "Reading backwards:\n";
readDataBackwards($conn);
?>

The above example will output:

Reading forwards:
21    10    5
16    0     5
19    20    10

Reading backwards:
19    20    10
16    0     5
21    10    5

PDO::prepare() - Prepares a statement for execution and returns a statement object
PDOStatement::execute() - Executes a prepared statement
PDOStatement::fetchAll() - Returns an array containing all of the result set rows
PDOStatement::fetchColumn() - Returns a single column from the next row of a result set
PDOStatement::fetchObject() - Fetches the next row and returns it as an object.
PDOStatement::setFetchMode() - Set the default fetch mode for this statement

PDOStatement->fetchAll

PDOStatement->execute

Last updated: Fri, 06 Nov 2009

add a note User Contributed Notes
PDOStatement->fetch

lod
16-Jul-2008 06:33


A quick one liner to get the first entry returned.  This is nice for very basic queries.



<?php

$count = current($db->query("select count(*) from table")->fetch());

?>php

lozitskiys at gmail dot com
09-Jul-2008 02:21


I spent some hours trying to find out how to manipulate with BLOB fields using PDO.



Remember that you can't retreive BLOB data using something like this :



<?php

$sql = 'SELECT * FROM sometable LIMIT 1';

$stmt = $dbh->prepare($sql);

$stmt->execute();

$stmt->setAttribute(PDO::FETCH_ASSOC);

$row = $stmt->fetch();



$myFile = $row['file'];

?>



Instead of this you should try following approach:



<?php

$sql = "SELECT mime, file FROM sometable LIMIT 1"; 

$stmt = $dbh->prepare($sql); 

$stmt->execute(); 



$stmt->bindColumn(1, $mime,); 

$stmt->bindColumn(2, $file, PDO::PARAM_LOB); 



$stmt->fetch(); 



header('Content-type: '.$mime);

print $file; 



?>

josh
29-Apr-2008 09:02


Note that PDO::ATTR_STRINGIFY_FETCHES will NOT work for the MySQL driver. MySQL will always return strings because that is the behaviour of the core mysql PHP extension. See http://bugs.php.net/bug.php?id=44341

daltenho at yahoo dot com
28-Jan-2008 06:17


As an alternative to marcini's suggestion:



You can use:



        $dbh->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, true);



...on your PDO connection object to allow query buffering in MySQL. This will eliminate the problem of re-preparing an unclosed statement object.

Gerard van Beek
28-Oct-2007 10:42


If you to use a new instance of a class for a record you can use:



<?php

include_once("user.class");

$sth = $db->prepare("SELECT * FROM user WHERE id = 1");



/* create instance automatically */

$sth->setFetchMode( PDO::FETCH_CLASS, 'user');

$sth->execute();

$user = $sth->fetch( PDO::FETCH_CLASS );

$sth->closeCursor();

print ($user->id);



/* or create an instance yourself and use it */

$user= new user();

$sth->setFetchMode( PDO::FETCH_INTO, $user);

$sth->execute();

$user= $sth->fetch( PDO::FETCH_INTO );

$sth->closeCursor();

print ($user->id);

?>

BaBna
16-Aug-2007 09:52


When you do a SELECT query for one row, and want to check if it's there, you don't need to count the fetchAll() result, you can just check if $result->fetch() is true:

<?php

$bbnq = sprintf("SELECT login

FROM users

WHERE id = %u",27);

try

    { $req = $db_bbn->query($bbnq); }

catch (Exception $e)

    { bbnf_pdo_error($e,__FILE__,__LINE__); }

if ( $r = $req->fetch() )

    { echo "This query has a row result"; }

else

    { echo "This query has an empty result"; }

?>

jdriddle_producer at yahoo dot com
09-Aug-2007 02:33


Oops... 



The constants are no longer PDO_FETCH_*



They are now class contants PDO::FETCH_*



The documentation above need to be changed appropriately.

jdriddle_producer at yahoo dot com
09-Aug-2007 02:28


>> note that fetch constants are not included in the PDO class for PHP versions prior to 5.1



They appear to not exist in 5.2.3 either, as I am getting the following error:



Notice: Use of undefined constant PDO_FETCH_ASSOC - assumed 'PDO_FETCH_ASSOC' in C:\Documents and Settings\driddle.AUTISMSPEAKS.000\My Documents\ascentral\sqlite_test.php on line 36



Warning: PDOStatement::fetchAll() expects parameter 1 to be long, string given in C:\Documents and Settings\driddle.AUTISMSPEAKS.000\My Documents\ascentral\sqlite_test.php on line 36'



Code to reproduce:



// retrieve and output info from db

$sqlGetEvent = 'SELECT * from calendarItem';

$result = $dbHandle->query($sqlGetEvent);

$data = $result->fetchAll(PDO_FETCH_ASSOC);

dennis at inmarket dot lviv dot ua
07-Apr-2007 03:18


Regarding the two previous notes - I downloaded the "latest CVS" a week ago for Windows and was surprised to notice that this issue is gone there, ie you don't have to close cursor before doing next query.

redcube
05-Apr-2007 11:53


as an alternative for marcini's note:



just clear the statement variable before you issue another query:



<?php



$stmt = $db->prepare('SELECT * FROM test');



// fetch only the first row

$row = $stmt->fetch(PDO::FETCH_ASSOC);



// clear the variable so its contents are destroyed (including the other rows in the result)

$stmt = null;



// now you can issue another query

$stmt = $db->prepare('SELECT * FROM test2');

?>

marcini
02-Apr-2007 01:41


Be careful with fetch() when you use prepared statements and MySQL (I don`t know how it is with other databases). Fetch won`t close cursor and won`t let you send any other query, even if your result set has only one row, . 

If you use $statement->fetch(), you will also have to use $statement->closeCursor() afterwards, to be albe to execute another query.

Alternatively you can use $statement->fetchAll() without $statement->closeCursor().

terry at bitsoup dot com
02-Mar-2006 09:46


WARNING:

fetch() does NOT adhere to SQL-92 SQLSTATE standard when dealing with empty datasets.



Instead of setting the errorcode class to 20 to indicate "no data found", it returns a class of 00 indicating success, and returns NULL to the caller.



This also prevents the exception mechainsm from firing.



Programmers will need to explicitly code tests for empty resultsets after any fetch*() instead of relying on the default behavior of the RDBMS.



I tried logging this as a bug, but it was dismissed as "working as intended". Just a head's up.

avinoamr at gmail dot com
19-Jan-2006 11:48


Note that using the FETCH_CLASS mechanism does NOT trigger the class's constructor! You must explicity instantiate the class to use it's constructor behavior.

fh at ez dot no
25-Nov-2005 09:13


I can also add that the constructor is run _after_ the data is set on the object if yo use PDO::FETCH_CLASS.

fh at ez dot no
25-Nov-2005 08:58


If you want to use PDO::FETCH_CLASS you need to set it up with setFetchMode first like so:

        $stmt->setFetchMode( PDO::FETCH_CLASS, 'classType', array( 'parameters to constructor' );

        $object = $stmt->fetch( PDO::FETCH_CLASS );

If you ommit this PHP will segfault.

aledmb at gmail dot com
21-Oct-2005 07:22


note that fetch constants are not included in the PDO class for PHP versions prior to 5.1

add a note

PDOStatement->fetchAll

PDOStatement->execute

Last updated: Fri, 06 Nov 2009

PDOStatement->fetch

Description

Parameters

Return Values

Examples

See Also