PDOStatement::fetchAll
(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.1.0)
PDOStatement::fetchAll — Fetches the remaining rows from a result set
Description
$mode
= PDO::FETCH_DEFAULT): array$mode
= PDO::FETCH_COLUMN, int $column
): array$mode
= PDO::FETCH_CLASS, string $class
, ?array $constructorArgs
): arrayParameters
-
mode
-
Controls the contents of the returned array as documented in PDOStatement::fetch(). Defaults to value of
PDO::ATTR_DEFAULT_FETCH_MODE
(which defaults toPDO::FETCH_BOTH
)To return an array consisting of all values of a single column from the result set, specify
PDO::FETCH_COLUMN
. You can specify which column you want with thecolumn
parameter.To fetch only the unique values of a single column from the result set, bitwise-OR
PDO::FETCH_COLUMN
withPDO::FETCH_UNIQUE
.To return an associative array grouped by the values of a specified column, bitwise-OR
PDO::FETCH_COLUMN
withPDO::FETCH_GROUP
. -
args
-
This argument has a different meaning depending on the value of the
mode
parameter:-
PDO::FETCH_COLUMN
: Returns the indicated 0-indexed column. -
PDO::FETCH_CLASS
: Returns instances of the specified class, mapping the columns of each row to named properties in the class. -
PDO::FETCH_FUNC
: Returns the results of calling the specified function, using each row's columns as parameters in the call.
-
-
constructorArgs
-
Arguments of custom class constructor when the
mode
parameter isPDO::FETCH_CLASS
.
Return Values
PDOStatement::fetchAll() returns an array containing all of the remaining rows in the result set. The array represents each row as either an array of column values or an object with properties corresponding to each column name. An empty array is returned if there are zero results to fetch.
Using this method to fetch large result sets will result in a heavy demand on system and possibly network resources. Rather than retrieving all of the data and manipulating it in PHP, consider using the database server to manipulate the result sets. For example, use the WHERE and ORDER BY clauses in SQL to restrict results before retrieving and processing them with PHP.
Changelog
Version | Description |
---|---|
8.0.0 |
This method always returns an array now, while previously false may have
been returned on failure.
|
Examples
Example #1 Fetch all remaining rows in a result set
<?php
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();
/* Fetch all of the remaining rows in the result set */
print("Fetch all of the remaining rows in the result set:\n");
$result = $sth->fetchAll();
print_r($result);
?>
The above example will output something similar to:
Fetch all of the remaining rows in the result set: Array ( [0] => Array ( [name] => apple [0] => apple [colour] => red [1] => red ) [1] => Array ( [name] => pear [0] => pear [colour] => green [1] => green ) [2] => Array ( [name] => watermelon [0] => watermelon [colour] => pink [1] => pink ) )
Example #2 Fetching all values of a single column from a result set
The following example demonstrates how to return all of the values of a single column from a result set, even though the SQL statement itself may return multiple columns per row.
<?php
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();
/* Fetch all of the values of the first column */
$result = $sth->fetchAll(PDO::FETCH_COLUMN, 0);
var_dump($result);
?>
The above example will output something similar to:
Array(3) ( [0] => string(5) => apple [1] => string(4) => pear [2] => string(10) => watermelon )
Example #3 Grouping all values by a single column
The following example demonstrates how to return an associative array
grouped by the values of the specified column in the result set. The
array contains three keys: values apple
and
pear
are returned as arrays that contain two
different colours, while watermelon
is
returned as an array that contains only one colour.
<?php
$insert = $dbh->prepare("INSERT INTO fruit(name, colour) VALUES (?, ?)");
$insert->execute(array('apple', 'green'));
$insert->execute(array('pear', 'yellow'));
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();
/* Group values by the first column */
var_dump($sth->fetchAll(PDO::FETCH_COLUMN|PDO::FETCH_GROUP));
?>
The above example will output something similar to:
array(3) { ["apple"]=> array(2) { [0]=> string(5) "green" [1]=> string(3) "red" } ["pear"]=> array(2) { [0]=> string(5) "green" [1]=> string(6) "yellow" } ["watermelon"]=> array(1) { [0]=> string(5) "pink" } }
Example #4 Instantiating a class for each result
The following example demonstrates the behaviour of the
PDO::FETCH_CLASS
fetch style.
<?php
class fruit {
public $name;
public $colour;
}
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();
$result = $sth->fetchAll(PDO::FETCH_CLASS, "fruit");
var_dump($result);
?>
The above example will output something similar to:
array(3) { [0]=> object(fruit)#1 (2) { ["name"]=> string(5) "apple" ["colour"]=> string(5) "green" } [1]=> object(fruit)#2 (2) { ["name"]=> string(4) "pear" ["colour"]=> string(6) "yellow" } [2]=> object(fruit)#3 (2) { ["name"]=> string(10) "watermelon" ["colour"]=> string(4) "pink" } [3]=> object(fruit)#4 (2) { ["name"]=> string(5) "apple" ["colour"]=> string(3) "red" } [4]=> object(fruit)#5 (2) { ["name"]=> string(4) "pear" ["colour"]=> string(5) "green" } }
Example #5 Calling a function for each result
The following example demonstrates the behaviour of the
PDO::FETCH_FUNC
fetch style.
<?php
function fruit($name, $colour) {
return "{$name}: {$colour}";
}
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();
$result = $sth->fetchAll(PDO::FETCH_FUNC, "fruit");
var_dump($result);
?>
The above example will output something similar to:
array(3) { [0]=> string(12) "apple: green" [1]=> string(12) "pear: yellow" [2]=> string(16) "watermelon: pink" [3]=> string(10) "apple: red" [4]=> string(11) "pear: green" }
See Also
- PDO::query() - Prepares and executes an SQL statement without placeholders
- PDOStatement::fetch() - Fetches the next row from a result set
- PDOStatement::fetchColumn() - Returns a single column from the next row of a result set
- PDO::prepare() - Prepares a statement for execution and returns a statement object
- PDOStatement::setFetchMode() - Set the default fetch mode for this statement