PDO Merging Results in to One Array - php

Question

I have a query result. Here is my code.
$P = new Product();
echo "<pre>";
print_r($P->get_product_image_path(1));
echo "</pre>";
In Product Class i have this function.
public function get_product_image_path($productid){
$sql = "SELECT picture FROM ".PREFIX."product_picture WHERE product_id = :id";
$this->query($sql);
$this->bind(':id', $productid);
if ($this->rowCount() > 0)
return $this->queryResults();
else
return NULL;
}
Here is my database class functions
public function query($sql)
{
return $this->_sql = $this->getPdo()->prepare($sql);
}
public function bind($param, $value, $type = null){
if (is_null($type)) {
switch (true) {
case is_int($value):
$type = PDO::PARAM_INT;
break;
case is_bool($value):
$type = PDO::PARAM_BOOL;
break;
case is_null($value):
$type = PDO::PARAM_NULL;
break;
default:
$type = PDO::PARAM_STR;
}
}
$this->_sql->bindValue($param, $value, $type);
}
public function execute(){
return $this->_sql->execute();
}
public function queryResults(){
$this->execute();
return $this->_sql->fetchAll(PDO::FETCH_ASSOC);
}
The result is returning
Array
(
[0] => Array
(
[picture] => 1328630682_1_xl.jpg
)
[1] => Array
(
[picture] => 1328630696_1_xl.jpg
)
[2] => Array
(
[picture] => 1328630689_1_xl.jpg
)
)
But i want to merge results like that
Array
(
[0] => 1328630682_1_xl.jpg
[1] => 1328630696_1_xl.jpg
[2] => 1328630689_1_xl.jpg
)
How can i do that. I'm new on PDO that's why i couldn't do it.

Answer 1

get rid of your database class.
do not extend your product class from database class.
use PDO to get an array in the desired form
here it goes
public function get_product_image_path($productid)
{
$sql = "SELECT picture FROM ".PREFIX."product_picture WHERE product_id = :id";
$stm = $this->pdo->prepare($sql);
$stm->execute(array($productid));
return $stm->fetchAll(PDO::FETCH_COLUMN, 0);
}
$pdo = new PDO(...);
$P = new Product($pdo);
echo "<pre>";
print_r($P->get_product_image_path(1));
echo "</pre>";

Answer 2

I wrote a new database class function
public function queryColumn($index = NULL){
$index = (isset($index)) ? intval($index) : 0;
$this->execute();
return $this->_sql->fetchAll(PDO::FETCH_COLUMN,$index);
}
And i edited my function
public function get_product_image_path($productid){
$sql = "SELECT picture FROM ".PREFIX."product_picture WHERE product_id = :id";
$this->query($sql);
$this->bind(':id', $productid);
if ($this->rowCount() > 0)
return $this->queryColumn();
else
return NULL;
}
Hence, i manage to merging arrays.