PHP PDO MYSQL - Get Array comma separated from fetchAll -

i'm stuck in this.

i need result (138,139,140,141,142,143,144,145), i'm getting (array,array,array,array,array,array,array,array)...

my code is:

<?php     try {                         $dbconn = dbconnection();                          $sql = "select `product_category_id`, `product_category_parent_id`, `date_available`, `status`                                  `product_category`                                  `product_category_parent_id` = '" . $_get['cat'] . "'                                  , `date_available` <= now()                                  , `status` = '1'                                  order `product_category_id` asc";                          $stmt = $dbconn -> prepare($sql);                         $stmt -> execute();                         $array = $stmt -> fetchall(pdo::fetch_assoc);                          foreach($array $row) {                             $category[] = array($row['product_category_id']);                         }                          $subcategory = implode(',', $category);                         echo $subcategory;     } ?> 

can please me?

thanks lot!

change

$category[] = array($row['product_category_id']); 

for

$category[] = $row['product_category_id'];