Description:
------------
If you do an OUTER LEFT JOIN and set PDO FetchALL to PDO::FETCH_ASSOC, any primary keys you used in the OUTER LEFT JOIN will be set to a blank if there are no records returned in the JOIN.
If we are joining using a field called "product_id" from a product table to an image table using an outer left join, and no records exist for that "product_id" in the image table, the product id comes back as blank in the resulting array

Reproduce code:
---------------
//query the product table and join to the image table and return any images, if we have any, for each product. Assume the image table contains no records

$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);
?>




Expected result:
----------------
Array
(
    [0] => Array
        (
            [product_id] => 16
            [notes] => "this product..."
            [brand] => "Best Yet"
            ...

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