Pagination object oriented

Question

This a little pagination script that I am writing "Object Oriented" and I have no idea how to set the current page equal to total page, if the current page is greater. I also would really like it if anyone can tell me how to improve my code.

class pagination extends Db_connection {
 public $per_page;
 public $current_page;
 public $sql;
 //put your code here
 function __construct($per = 3, $current = 1) {
 parent::__construct();
 $this->per_page = $per;
 $this->current_page = $current;
 }
 function execute_query($sql) {
 $this->sql = $sql;
 $q = $this->query($sql);
 return $q;
 }
 function total_pages() {
 $total = ceil($this->count_rows() / $this->per_page);
 return $total;
 }
 function current_page() {
 if (isset($_GET['page']) && is_numeric($_GET['page'])) 
 $this->current_page = intval($_GET['page']); 
 return $this->current_page;
 }
 function offset() {
 $off = ($this->current_page() - 1) * $this->per_page;
 return $off;
 }
 public function previous_page(){
 //move to previous record by subtracting one into the current record
 return $this->current_page - 1;
 }
 public function next_page(){
 //mvove to next record by incrementing the current page by one 
 return $this->current_page + 1;
 }
 function count_rows() {
 $nums = mysqli_fetch_row($this->execute_query("select count(post_id) from Post"));
 return $nums[0];
 }
 function results() {
 $off = $this->offset();
 $per = $this->per_page;
 $query = $this->execute_query("Select * from Post limit $off, $this->per_page");
 while ($result = mysqli_fetch_array($query)) {
 $data[] = $result;
 }
 return $data;
 }
}

• Phrancis: The tiny amount of SQL you have in there looks fine, for all that it's worth. I don't know much about PHP but I'll try to tag someone who does.

Answer 1

If you have to identify the main objects here, we could conclude that you have at least 3

-- The connection to the DataBase

-- The pagination object that knows how to paginate a query

-- The query it self

so ie this is a possible solution:

abstract class DBConnection{
 //Logic 
 public function executeQuery(Query $query)
 {
 $sql = $query->getSql();
 //Logic and return results
 }
}
class Query{
 private $sql;
 private $limit;
 private $offset;
 //getters and setters for each private property ... getSql ... setSql ...
 public function __construct($sql)
 {
 $this->sql = $sql;
 }
 public function getSql()
 {
 return $this->sql += "offset $this->getOffset() limit $this->getLimit()";
 }
}
class Paginator
{
 private $currentPage;
 private $perPage;
 private $query;
 private $connection;
 //Getters and setters...
 public function __construct(Query $query, $currentPage = 0, $perPage = 10)
 {
 $this->query = $query;
 $this->connection = new DBConnection();
 }
 public function nextPage()
 {
 $this->currentPage++;
 }
 public function prevPage()
 {
 $this->currentPage--; //check if 0 not substract
 }
 public function execute()
 {
 $this->query->setOffset($this->currentPage * $this->perPage);
 $this->query->setLimit($this->perPage);
 return $this->connection->executeQuery($this->query);
 }
}

• mdfst13: Hi! It's helpful if rather than just dumping a lump of code that you post what changes you are making and why. The why is especially important here, as we are reviewing code more than writing it.