数组转换删除索引

下面的函数,即getBooksInsertedCount代码给出如下输出

  array(3) {
  [0]=>
  string(1) "1"
  [1]=>
  string(1) "2"
  [2]=>
  string(1) "1"
}

GetBooksInsertedCount

function getBooksInsertedCount()
{  
  $this->load->database();    
  $query = "SELECT count(book_id) as count,date(created_date) as cdate FROM `bookdetails` WHERE  (created_date BETWEEN '2018-06-25' AND '2018-06-28') GROUP by created_date order by created_date asc";
  $result = $this->db->query($query);
 $ret = array();

   foreach ($result->result_array() as $row ) {
            $ret[] = $row['count'];
   } 
     return $ret;
  }

预期输出(注意:[0]=>字符串(1)已删除)

array(1, 2, 1);