Displays id of all products by category id?

Question

PHP

Hi all!
I am trying to make a sql query but the result is zero
code

public function getProductCategory($category_id) {
    $query = $this->db->query("SELECT * FROM " . DB_PREFIX . "product_to_category WHERE product_id = '" . (int)$category_id . "'");

    return $query->rows;
  }

Here is the table prntscr.com/h31zm8 from here you need to select all products by category_id.

Answer 1

select all products by category_id

Well, really?
Go relax, take a walk or sleep.

Answer 2

$query = $this->db->query("SELECT * FROM " . DB_PREFIX . "product_to_category WHERE category_id = '" . (int)$category_id . "'");