PDOStatement::fetchAll

(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.1.0)

PDOStatement::fetchAll — 結果セットから、残っている行を取得する

説明

public PDOStatement::fetchAll(int $mode = PDO::FETCH_DEFAULT): array

public PDOStatement::fetchAll(int $mode = PDO::FETCH_COLUMN, int $column): array

public PDOStatement::fetchAll(int $mode = PDO::FETCH_CLASS, string $class, ?array $constructorArgs): array

public PDOStatement::fetchAll(int $mode = PDO::FETCH_FUNC, callable $callback): array

パラメータ

mode

PDOStatement::fetch() で説明されている、返される配列の内容を制御します。デフォルトは PDO::ATTR_DEFAULT_FETCH_MODE の値 (デフォルトは PDO::FETCH_BOTH) です。

結果セットから単一カラムの全ての値を含む配列を返す場合、 PDO::FETCH_COLUMN を指定します。 column パラメータにどのカラムを返すかを指定することができます。

配列のキーに(連続した数値ではなく)あるカラムの値を割り当てたい場合 SQL のカラムリスト中のカラム名を指定すると同時に PDO::FETCH_UNIQUE を指定します。このカラムはユニークである必要があります。そうしないと、データが失われます。

指定したカラムの値によってグループ化した3次元配列を返す場合、 SQL のカラムリスト中のカラム名を指定すると同時に PDO::FETCH_GROUP を指定します。

結果をグループ化した2次元配列で返す場合、 PDO::FETCH_COLUMN と一緒に PDO::FETCH_GROUP bit-OR で指定します。この結果は、最初のカラムでグループ化され、配列の要素の値はふたつめのカラムの対応するエントリの配列になります。

以下は mode の値によって決まる動的なパラメータです。これらは、名前付き引数と一緒に使うことは出来ません。

column: PDO::FETCH_COLUMN と一緒に使います。0 から始まる番号のカラムを返します。
class: PDO::FETCH_CLASS と一緒に使います。ここで指定したクラスのインスタンスを返します。各行のカラムがクラスのプロパティ名にマッピングされます。
constructorArg: mode が PDO::FETCH_CLASS のときに使う、独自のクラスコンストラクタへの引数。
callback: PDO::FETCH_FUNC と一緒に使います。ここで指定した関数をコールした結果を返します。各行のカラムを関数コール時のパラメータとします。

戻り値

PDOStatement::fetchAll() は、結果セットに残っている全ての行を含む配列を返します。この配列は、カラム値の配列もしくは各カラム名に対応するプロパティを持つオブジェクトとして各行を表します。取得結果がゼロ件だった場合は空の配列を返します。

大きな結果セットをフェッチするためにこのメソッドを使用することは、システムとネットワークリソースに大量の要求を行うことになります。 PHP で全てのデータ処理と操作を行うよりも、データベースサーバー側で結果セットを操作することを検討してください。例えば、PHP で処理を行う前に SQL で WHERE 句や ORDER BY 句を使用し、結果を制限することです。

エラー / 例外

PDO::ATTR_ERRMODE が PDO::ERRMODE_WARNING に設定されていた場合、E_WARNING レベルのエラーが発生します。

PDO::ATTR_ERRMODE が PDO::ERRMODE_EXCEPTION に設定されていた場合、PDOException がスローされます。

変更履歴

バージョン	説明
8.0.0	このメソッドは、常に配列を返すようになりました。これより前のバージョンでは、失敗した場合に `false` を返す可能性がありました。

例

例1 結果セットに残っている全ての行をフェッチする

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

/* 結果セットに残っている全ての行をフェッチする */
print "Fetch all of the remaining rows in the result set:\n";
$result = $sth->fetchAll();
print_r($result);
?>

上の例の出力は、たとえば以下のようになります。

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
        )

)

例2 結果セットから単一カラムの全ての値を取得する

以下の例は、 SQL ステートメント自身が行毎に複数のカラムを返す場合において、どのように結果セットから単一カラムの全ての値を取得するかを例示しています。

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

/* 最初のカラムの全ての値を取得する */
$result = $sth->fetchAll(PDO::FETCH_COLUMN, 0);
var_dump($result);
?>

上の例の出力は、たとえば以下のようになります。

Array(3)
(
    [0] =>
    string(5) => apple
    [1] =>
    string(4) => pear
    [2] =>
    string(10) => watermelon
)

例3 単一カラムによる全ての値のグループ化

以下の例は、どのように結果セット中の特定のカラムの値によってグループ化された連想配列を返すかを例示しています。その配列は 3 つのキーを有します。値 apple、 pear は異なる 2 つの異なる色を有する配列として返され、一方 watermelon は 1 つの色のみ有する配列として返されます。

<?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();

/* 最初のカラムの値によってグループ化する */
var_dump($sth->fetchAll(PDO::FETCH_COLUMN|PDO::FETCH_GROUP));
?>

上の例の出力は、たとえば以下のようになります。

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"
  }
}

例4 各結果用のクラスのインスタンス作成

次の例は、 PDO::FETCH_CLASS の振る舞いを示すものです。

<?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);
?>

上の例の出力は、たとえば以下のようになります。

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"
  }
}

例5 各結果に対する関数コール

次の例は、 PDO::FETCH_FUNC の振る舞いを示すものです。

<?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);
?>

上の例の出力は、たとえば以下のようになります。

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"
}

参考

PDO::query() - プレースホルダを指定せずに、SQL ステートメントを準備して実行する
PDOStatement::fetch() - 結果セットから次の行を取得する
PDOStatement::fetchColumn() - 結果セットの次行から単一カラムを返す
PDO::prepare() - 文を実行する準備を行い、文オブジェクトを返す
PDOStatement::setFetchMode() - この文に対するデフォルトのフェッチモードを設定する

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User Contributed Notes 19 notes

down

101

simplerezo at gmail dot com ¶

7 years ago

I still don't understand why FETCH_KEY_PAIR is not documented here (http://php.net/manual/fr/pdo.constants.php), because it could be very useful!

<?php
  var_dump($pdo->query('select id, name from table')->fetchAll(PDO::FETCH_KEY_PAIR));
?>

This will display:
array(2) {
  [2]=>
  string(10) "name2"
  [5]=>
  string(10) "name5"
}

down

dyukemedia at gmail dot com ¶

10 years ago

Getting foreach to play nicely with some data from PDO FetchAll()
I was not understanding to use the $value part of the foreach properly, I hope this helps someone else.
Example:
<?php 
$stmt = $this->db->prepare('SELECT title, FMarticle_id FROM articles WHERE domain_name =:domain_name');
            $stmt->bindValue(':domain_name', $domain);
            $stmt->execute();
            $article_list = $stmt->fetchAll(PDO::FETCH_ASSOC);
?>
which gives:

array (size=2)
  0 => 
    array (size=2)
      'title' => string 'About Cats Really Long title for the article' (length=44)
      'FMarticle_id' => string '7CAEBB15-6784-3A41-909A-1B6D12667499' (length=36)
  1 => 
    array (size=2)
      'title' => string 'another cat story' (length=17)
      'FMarticle_id' => string '0BB86A06-2A79-3145-8A02-ECF6EA5C405C' (length=36)

Then use:
<?php
foreach ($article_list as $row => $link) {
  echo  '<a href="'.  $link['FMarticle_id'].'">' . $link['title']. '</a></br>';
  }
?>

down

esw at pixeloution dot removeme dot com ¶

14 years ago

Interestingly enough, when you use fetchAll, the constructor for your object is called AFTER the properties are assigned. For example:

<?php
class person {
    public $name;

    function __construct() {
       $this->name = $this->name . " is my name.";
    }
}

# set up select from a database here with PDO
$obj = $STH->fetchALL(PDO::FETCH_CLASS, 'person');
?>

Will result in ' is my name' being appended to all the name columns. However if you call it slightly differently:

<?php
$obj = $obj = $STH->fetchAll(PDO::FETCH_CLASS | PDO::FETCH_PROPS_LATE, 'person');
?>

Then the constructor will be called before properties are assigned. I can't find this documented anywhere, so I thought it would be nice to add a note here.

down

Daniel Hofmann ¶

15 years ago

PLEASE BE AWARE: If you do an OUTER LEFT JOIN and set PDO FetchALL to PDO::FETCH_ASSOC, any primary key you used in the OUTER LEFT JOIN will be set to a blank if there are no records returned in the JOIN.

For example:
<?php
//query the product table and join to the image table and return any images, if we have any, for each product
$sql = "SELECT * FROM product, image
LEFT OUTER JOIN image ON (product.product_id = image.product_id)";

$array = $stmt->fetchAll(PDO::FETCH_ASSOC);

print_r($array);
?>

The resulting array will look something like this:

Array
(
    [0] => Array
        (
            [product_id] => 
            [notes] => "this product..."
            [brand] => "Best Yet"
            ...

The fix is to simply specify your field names in the SELECT clause instead of using the * as a wild card, or, you can also specify the field in addition to the *. The following example returns the product_id field correctly:

<?php
$sql = "SELECT *, product.product_id FROM product, image
LEFT OUTER JOIN image ON (product.product_id = image.product_id)";

$array = $stmt->fetchAll(PDO::FETCH_ASSOC);

print_r($array);
?>

The resulting array will look something like this:

Array
(
    [0] => Array
        (
            [product_id] => 3
            [notes] => "this product..."
            [brand] => "Best Yet"
            ...

down

Anonymous ¶

13 years ago

Note that fetchAll() can be extremely memory inefficient for large data sets. My memory limit was set to 160 MB this is what happened when I tried:



<?php

$arr = $stmt->fetchAll();

// Fatal error: Allowed memory size of 16777216 bytes exhausted

?>



If you are going to loop through the output array of fetchAll(), instead use fetch() to minimize memory usage as follows:



<?php

while ($arr = $stmt->fetch()) {

    echo round(memory_get_usage() / (1024*1024),3) .' MB<br />';

    // do_other_stuff();

}

// Last line for the same query shows only 28.973 MB usage

?>

down

michael dot arnauts at gmail dot com ¶

10 years ago

If you want to use PDO::FETCH_CLASS but don't like that all the values are of the type string, you can always use the __construct function of the class specified to convert them to a different type.

Another way is using mysqlnd, but it seems I had to recompile PHP for that.

<?php

class Cdr {
    public $a; // int
    public $b; // float
    public $c; // string
    
    public function __construct() {
        $this->a = intval($this->a);
        $this->b = floatval($this->b);
    }
     
}

// ...
$arrCdrs = $objSqlStatement->fetchAll(PDO::FETCH_CLASS, 'Cdr');

?>

down

info at yuriblanc dot it ¶

9 years ago

Something missing in the doc.
If for instance you try to fetchAll(PDO::CLASS, "Class") it sometimes return an array of objects with NULL values, but the count of objects fetched correspond to table rows.

In this way works fine:
fetchAll(PDO::FETCH_CLASS | PDO::FETCH_PROPS_LATE, "Class");

For example

$stm = $pdo->prepare("SELECT * FROM Fruit");
$stm->execute();
$stm->fetchAll(PDO::FETCH_CLASS | PDO::FETCH_PROPS_LATE, "Fruit");

down

Anonymous ¶

17 years ago

If no rows have been returned, fetchAll returns an empty array.

down

shaunc ¶

2 years ago

Note that \PDO::FETCH_DEFAULT was not introduced until PHP 8.0.7 and 8.1.0. It will throw an undefined constant error in earlier versions.

down

Anonymous ¶

7 years ago

Be careful when using PDO::FETCH_COLUMN with PDO::FETCH_GROUP. By default, results are grouped by first column (index 0) and second column (index 1) is returned. But, if you provide fetch argument, it wouldn't affect returned column, but grouping column. If grouping column is set explicitly , first columns is returned instead of second.

<?php
$insert = $dbh->prepare("INSERT INTO people(id, gender) VALUES (?, ?)");
$insert->execute(array('2', 'female'));
$insert->execute(array('3', 'female'));
$insert->execute(array('4', 'female'));
$insert->execute(array('5', 'male'));
$insert->execute(array('6', 'male'));

$sth = $dbh->prepare("SELECT gender, id FROM people");
$sth->execute();

/* Group values by the first column */
var_dump($sth->fetchAll(PDO::FETCH_COLUMN|PDO::FETCH_GROUP));
?>
Returns:
<?php
array (size=2)
  'female' => 
    array (size=3)
      0 => string '2' (length=1)
      1 => string '3' (length=1)
      2 => string '4' (length=1)
  'male' => 
    array (size=2)
      0 => string '5' (length=1)
      1 => string '6' (length=1)
?>

But, 
<?php
var_dump($sth->fetchAll(PDO::FETCH_COLUMN|PDO::FETCH_GROUP, 0));
?>
returns:
<?php 
array (size=2)
  'female' => 
    array (size=3)
      0 => string 'female' (length=1)
      1 => string 'female' (length=1)
      2 => string 'female' (length=1)
  'male' => 
    array (size=2)
      0 => string 'male' (length=1)
      1 => string 'male' (length=1)
?>
and 
<?php 
var_dump($sth->fetchAll(PDO::FETCH_COLUMN|PDO::FETCH_GROUP, 1));
?>
returns
<?php
array (size=5)
  2 => 
    array (size=1)
      0 => string 'female' (length=1)
  3 => 
    array (size=1)
      0 => string 'female' (length=1)
  4 => 
    array (size=1)
      0 => string 'female' (length=1)
  5 => 
    array (size=1)
      0 => string 'male' (length=1)
  6 => 
    array (size=1)
      0 => string 'male' (length=1)
?>

First column is retuned and grouping is done by provided column index.

down

rudigerw at hotmail dot com ¶

6 years ago

I was blown away that you can actually combine PDO::FETCH_CLASS | PDO::FETCH_CLASSTYPE | PDO::FETCH_UNIQUE, because both PDO::FETCH_CLASSTYPE and PDO::FETCH_UNIQUE say they will use the first column, but it turns out PDO::FETCH_CLASSTYPE goes first and then PDO::FETCH_UNIQUE will use the next column. This way you can create an associative array of objects, with one of the table columns as key. For example a query such as

 'SELECT Class, Id, t.* FROM subscriptions_tbl t'

might give you this result:

Array
(
    [20481086] => WConsumerSubscription Object
        (
            [Variant] => 2
            [_Expiration:WSubscriptionModel:private] => DateTime Object
                (
                    [date] => 2018-08-08 00:00:00.000000
                    [timezone_type] => 3
                    [timezone] => UTC
                )

            [Notes] => 
            [Id] => 20481086
            [_Deleted:protected] => 0
            [_VersionNo:protected] => 2
            [ContactId] => 
            [ConsumerId] => 2
        )

    [21878324] => WAdminSubscription Object
        (
            [Variant] => 
            [_Expiration:WSubscriptionModel:private] => 
            [Notes] => 
            [Id] => 21878324
            [_Deleted:protected] => 0
            [_VersionNo:protected] => 1
            [ContactId] => 
        )
)

down

Hayley Watson ¶

13 years ago

If you use the PDO::FETCH_CLASS | PDO::FETCH_PROPS_LATE flags to map columns to object properties, fetchAll() will use any __set() method your object has when carrying out the mapping.

down

mxrgus ¶

15 years ago

In method body:

return $pstmt->fetchAll() or die("bad");

will not return correct value, but "1" instead.

down

stas at metalinfo dot ru ¶

18 years ago

Note, that you can use PDO::FETCH_COLUMN|PDO::FETCH_GROUP pair only while selecting two columns, not like DB_common::getAssoc(), when grouping is set to true.

down

harlequin2 at gmx dot de ¶

16 years ago

There is also another fetch mode supported on Oracle and MSSQL: 
PDO::FETCH_ASSOC

> fetches only column names and omits the numeric index.

If you would like to return all columns from an sql statement with column keys as table headers, it's as simple as this:

<?php
$dbh = new PDO("DS", "USERNAME", "PASSWORD");
$stmt = $dbh->prepare("SELECT * FROM tablename");
$stmt->execute();
$arrValues = $stmt->fetchAll(PDO::FETCH_ASSOC);
// open the table
print "<table wdith=\"100%\">\n";
print "<tr>\n";
// add the table headers
foreach ($arrValues[0] as $key => $useless){
    print "<th>$key</th>";
}
print "</tr>";
// display data
foreach ($arrValues as $row){
    print "<tr>";
    foreach ($row as $key => $val){
        print "<td>$val</td>";
    }
    print "</tr>\n";
}
// close the table
print "</table>\n";
?>

down

akira at etnforum dot com ¶

9 years ago

There may be some user who needs to upgrade their MySQL class to PDO class. The way of fetching results were changed from while loop into a foreach loop. For the people who wish to fetch the results in a while loop, here is a simple trick.

<?php

$db = new DB();
$query = $db->prepare("SELECT * FROM CPUCategory");
$query = $db->execute();
$result = $db->fetchAll();
var_dump($result);

?>

The Output will be:
array(2) {
    [0]=> array(2) {
        ["ccatid"]=> int(1)
        ["ccatname"]=> string(5) "Intel"
    }
    [1]=> array(2) {
        ["ccatid"]=> int(2) 
        ["ccatname"]=> string(3) "AMD"
    }
}

Never look like the output of old function.
[ORIGINAL STYLE] mysql_fetch_array($query)
[   MYSQL CLASS] $db->fetch_array($query)

And you may give up.
But there is a simple way to use while loop to fetch the results.

<?php

$db = new DB();
$query = $db->prepare("SELECT * FROM CPUCategory");
$query = $db->execute();
$result = $db->fetchAll();
$row = array_shift($result);
// If you need to fetch them now, put it in a while loop just like below:
// while($row = array_shift($result)) { ... }
    
var_dump($row);

?>

The Output will be in a single array with while loop returns TRUE:
array(2) {
    ["ccatid"]=> int(1)
    ["ccatname"]=> string(5) "Intel"
}

So after fetching this row, while loop runs again and fetch the next row until all row has fetched, then the while loop will return false. (Just like the old function did)

When you need to upgrade to PDO class, not much code needs to be modified and remember.

down

Dennis ¶

14 years ago

Error:
SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active. Consider using PDOStatement::fetchAll(). Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.

If you're using something like:

while ($row = $query->fetchObject()) {
    [...]
}

try using this instead:

$rows = $query->fetchAll(PDO::FETCH_CLASS, 'ArrayObject');

foreach ($rows as $row) {
    [...]
}

down

php at erikthiart dot com ¶

3 years ago

I am adding this here as I don’t seem to find any clear and easy to find examples and explanations of PDO::FETCH_GROUP and how it works by means of an example.

I find this to be one of the most useful modes available in fetchAll() when you need to work with any form of grouping.

In essence, PDO can group results into nested arrays, based on the first field selected.

Example

<?php

$data = $pdo->query('SELECT sex, name, car FROM users')->fetchAll(PDO::FETCH_GROUP);

/* array (
  'male' => array ( 0 => 
    array (
      'name' => 'John',
      'car' => 'Toyota',
    ),
    1 => array (
      'name' => 'Mike',
      'car' => 'Ford',
    ),
  ),
  'female' => array (
    0 => array (
      'name' => 'Mary',
      'car' => 'Mazda',
    ),
    1 => array (
      'name' => 'Kathy',
      'car' => 'Mazda',
    ),
  ),
) */

?>

Tip: If you need to group the data by something other than the first field then you can do it like this as well

<?php
SELECT sex, users.* FROM users
?>

down

Leonardo Costa linux at linuxmanbr dot com dot br ¶

5 years ago

Method with Return object (PHP 7.2)

class MySql {

public function __construct()
        {
            parent::__construct();
            
            try{

    
                
                $options = array
                (
                    PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES UTF8"
                );
                
                $this->pdo = new PDO('mysql:host=127.0.0.1;dbname=testuser','dbtest', 'xxxxxxx',$options);
                $this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
                
            }catch(PDOException $e) {
                print "Error!: " . $e->getMessage() . "<br/>";
                die();
            }
        }
        
        public function selectAll(string $sql)
        {
            $conn = $this->pdo->query($sql);
            return $conn->fetchAll(PDO::FETCH_OBJ);
        }
}

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