PDOStatement::fetchAll()

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

返回一个包含结果集中所有行的数组

说明

PDOStatement::fetchAll([int $fetch_style[,mixed $fetch_argument[,array $ctor_args= array()]]]): array

参数

$fetch_style

控制返回数组的内容如同PDOStatement::fetch()文档中记载的一样。默认为PDO::ATTR_DEFAULT_FETCH_MODE的值（其缺省值为PDO::FETCH_BOTH）

想要返回一个包含结果集中单独一列所有值的数组，需要指定PDO::FETCH_COLUMN。通过指定column-index参数获取想要的列。

想要获取结果集中单独一列的唯一值，需要将PDO::FETCH_COLUMN和PDO::FETCH_UNIQUE按位或。

想要返回一个根据指定列把值分组后的关联数组，需要将PDO::FETCH_COLUMN和PDO::FETCH_GROUP按位或。

$fetch_argument

根据$fetch_style参数的值，此参数有不同的意义：

• PDO::FETCH_COLUMN：返回指定以0开始索引的列。

• PDO::FETCH_CLASS：返回指定类的实例，映射每行的列到类中对应的属性名。

• PDO::FETCH_FUNC：将每行的列作为参数传递给指定的函数，并返回调用函数后的结果。

$ctor_args

当$fetch_style参数为PDO::FETCH_CLASS时，自定义类的构造函数的参数。

返回值

PDOStatement::fetchAll()返回一个包含结果集中所有剩余行的数组。此数组的每一行要么是一个列值的数组，要么是属性对应每个列名的一个对象。

使用此方法获取大结果集将导致系统负担加重且可能占用大量网络资源。与其取回所有数据后用PHP来操作，倒不如考虑使用数据库服务来处理结果集。例如，在取回数据并通过PHP处理前，在 SQL 中使用 WHERE 和 ORDER BY 子句来限定结果。

范例

获取结果集中所有剩余的行

<?php
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();
/* 获取结果集中所有剩余的行 */
print("Fetch all of the remaining rows in the result set:\n");
$result = $sth->fetchAll();
print_r($result);
?>

以上例程的输出类似于：

Fetch all of the remaining rows in the result set:
Array
(
    [0] => Array
        (
            [NAME] => pear
            [0] => pear
            [COLOUR] => green
            [1] => green
        )
    [1] => Array
        (
            [NAME] => watermelon
            [0] => watermelon
            [COLOUR] => pink
            [1] => pink
        )
)

获取结果集中单独一列的所有值

下面例子演示了如何从一个结果集中返回单独一列所有的值，尽管 SQL 语句自身可能返回每行多列。

<?php
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();
/* 获取第一列所有值 */
$result = $sth->fetchAll(PDO::FETCH_COLUMN, 0);
var_dump($result);
?>

以上例程的输出类似于：

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

根据单独的一列把所有值分组

下面例子演示了如何返回一个根据结果集中指定列的值分组的关联数组。该数组包含三个键：返回的apple和pear数组包含了两种不同的颜色，而返回的watermelon数组仅包含一种颜色。

<?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");
$sth->execute();
/* 根据第一列分组  */
var_dump($sth->fetchAll(PDO::FETCH_COLUMN|PDO::FETCH_GROUP));
?>

以上例程的输出类似于：

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) "green"
  }
}

每行结果实例化一个类

下面列子演示了PDO::FETCH_CLASS获取风格的行为。

<?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);
?>

以上例程的输出类似于：

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"
  }
}

每行调用一次函数

下面列子演示了PDO::FETCH_FUNC获取风格的行为。

<?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);
?>

以上例程的输出类似于：

array(3) {
  [0]=>
  string(12) "apple: green"
  [1]=>
  string(12) "pear: yellow"
  [2]=>
  string(16) "watermelon: pink"
}

参见

• PDO::query() 执行 SQL 语句，以 PDOStatement 对象形式返回结果集
• PDOStatement::fetch() 从结果集中获取下一行
• PDOStatement::fetchColumn() 从结果集中的下一行返回单独的一列。
• PDO::prepare() 准备要执行的语句，并返回语句对象
• PDOStatement::setFetchMode() 为语句设置默认的获取模式。

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"
}

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>';
 }
?>

You might find yourself wanting to use FETCH_GROUP and FETCH_ASSOC at the same time, to get your table's primary key as the array key:
<?php
// $stmt is some query like "SELECT rowid, username, comment"
$results = $stmt->fetchAll(PDO::FETCH_GROUP|PDO::FETCH_ASSOC);
// It does work, but not as you might expect:
$results = array(
  1234 => array(0 => array('username' => 'abc', 'comment' => '[...]')),
  1235 => array(0 => array('username' => 'def', 'comment' => '[...]')),
);
// ...but you can at least strip the useless numbered array out easily:
$results = array_map('reset', $results);
?>

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.

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"
      ...

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
?>

to fetch rows grouped by primary id or any other field you may use FETCH_GROUP with FETCH_UNIQUE:
<?php
//prepare and execute a statement returning multiple rows, on a single one
$stmt = $db->prepare('SELECT id,name,role FROM table');
$stmt->execute();
var_dump($stmt->fetchAll(PDO::FETCH_GROUP | PDO::FETCH_UNIQUE));
//returns an array with the first selected field as key containing associative arrays with the row. This mode takes care not to repeat the key in corresponding grouped array.
$result = array
 (1 => array
  ('name'=>'foo',
  'role'=>'sage',),
 2 => array
  ('name'=>'bar',
  'role'=>'rage',),);
// 'SELECT name,id,role FROM table' would result in that:
$result = array
 ('foo' => array
  ('id'=>1,
  'role'=>'sage',),
 'bar' => array
  ('id'=>2,
  'role'=>'rage',),);
?>

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

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.

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');
?>

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) {
  [...]
}

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";
?>

PHP fetchAll Data From SQL Server 2005 
if field's data type is varchar(nvarchar), only fetch 255 chars. but the "text" data type is ok.
so, notice! to change the 'varchar' or 'nvarchar' (length > 255) to 'text' data type..
hope to help u.
<?php
$user = 'sa';
$pass = 'pass';
$conn = new PDO('mssql:host=127.0.0.1; dbname=tempdb;', $user, $pass);
$mainSQL = "SELECT field_varchar, field_text FROM table1";
$sth = $conn->prepare($mainSQL);
$sth->setFetchMode(PDO::FETCH_ASSOC);
$sth->execute();
$retRows = $sth->fetchAll();
// the field_varchar field only to fetch 255 chars(max)
// the field_text is ok.
var_dump($retRows);
unset($sth); unset($conn);
?>

You might find yourself wanting to use FETCH_GROUP and FETCH_ASSOC at the same time, to get your table's primary key as the array key - use FETCH_UNIQUE also, or you will probably get some unintended behaivor:
<?php
// $stmt is some query like "SELECT rowid, username, comment"
//with unique
$results = $stmt->fetchAll(PDO::FETCH_GROUP|PDO::FETCH_ASSOC|PDO::FETCH_UNIQUE);
$results = array(
  1234 => array('username' => 'abc', 'comment' => '[...]'),
  1235 => array('username' => 'def', 'comment' => '[...]'),
);
//without unique 
$results = $stmt->fetchAll(PDO::FETCH_GROUP|PDO::FETCH_ASSOC);
// It does work, but not as you might expect:
$results = array(
  1234 => array(0 => array('username' => 'abc', 'comment' => '[...]')),
  1235 => array(0 => array('username' => 'def', 'comment' => '[...]')),
);
?>
Credit to Ant P. for minimal Example (which i shamelessly copied from the note above me). Thanks a lot!

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.

I was having trouble with returning PDO query results in arrays, due to the structure of the results of those queries (query array with arrays for results inside). Now when executing a fetchAll() on a query you get the following: 
Array ( [0] = Array ( [key1] => "value1", [key2] => "value2") [1] = Array( [key1] => "value1", [key2] => "value2") )
This is a smaller array, but return results in a HUGE database this way and it quickly becomes IMPPOSIBRU to read out the array given.
This is where the glorious foreach comes in! We all know the basic writing of a foreach (foreach ($array as $key => $value) {...}), but with query results there's a twist, as both the $key AND $value variables are arrays, where $key is the array of the query containing the result arrays and $value is/are the result array(s) themselves.
So in this foreach we have to talk directly to $value to get our results! This would look something like this:
<?php
 foreach ($query as $key => $value) {
   return $value["key2"];
 }
?>
This already does the job, but to return them in arrays we have to change our return code a little bit, like so:
<?php
  foreach ($query as $key => $value) {
   return array (
       "key1" => $value["key1"],
       "key2" => $value["key2"]
   );
  }
?>
This foreach loops through the query array, just like the firs one, but the return code just doesn't return the keys representing the result arrays ($key) and returns only keys from inside the result arrays, stored in $value. This gives us an array looking like this:
Array ( [key1] => "value1", [key2] => "value2")
This should return all the values in your array, if written properly. I'm still having problems with the foreach not returning ALL results, but this note was mainly to show how it can be returned in an array.

In method body:
return $pstmt->fetchAll() or die("bad");
will not return correct value, but "1" instead.

If you want to fetch rows as an object for which you have not defined a class, you can do:
<?php
$result = $q->fetchAll(PDO::FETCH_OBJ);
?>

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.

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");

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.

When passing PDO::FETCH_CLASS as the first argument, this method will accept the class name as the second option:
<?php
$query = $pdo->prepare($sql);
$result = $query->execute($values);
if ($result && $query->rowCount() > 0) {
  $records = $query->fetchAll(PDO::FETCH_CLASS, 'Some_Class');
  // $record is now an array of Some_Class objects
}
?>
- Davey

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);
    }
}

Inject the parameters directly into `fetchAll` instead of using `bindValue`
$query = "
      SELECT 
          a.total_paid_tax_incl AS prize, 
          a.date_add AS date_add
      FROM orders a 
      WHERE a.order_id = :seventeen 
          AND a.name = :name";
// connection (Example in Symfony you use class Connection in namespace Doctrine\DBAL\Connection)
$this->connection->fetchAll($query, ['seventeen' => 70, 'name' => 'Sidi'])

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] => 
    )
)

If you would like to get the result as "key-value-pairs", like:
Array(
  [key1] => "value1"
  [key2] => "value2"
)
then you can do it by calling fetchAll with PDO::FETCH_GROUP | PDO::FETCH_COLUMN parameters. 
<?php
 $result = $query->fetchAll(PDO::FETCH_GROUP|PDO::FETCH_COLUMN);
?>

If you are trying to call PDOStatement::fetchAll and is not getting the result set as expected (empty instead), check if you called PDOStatement::execute first.
Remember PDOStatement::fetchAll does not execute the query, it just mounts the array. 
:)

Using fetchAll() with the fetch types PDO::FETCH_GROUP and PDO::FETCH_ASSOC, PDO::FETCH_CLASS will always use the first column in the selected table as the key for the row in the output...