split_page_results.php，实现分页
文件路径：\includes\classes\split_page_results.php
// 这是一个用于分页的类，其实分页的只是在依赖mysql的limit参数，其实这个分页是无法满足定制要求的，通常得修改
class splitPageResults extends base {
var $sql_query, $number_of_rows, $current_page_number, $number_of_pages, $number_of_rows_per_page, $page_name;
/* class constructor */
// 这个构造函数，对$query传入的查询语句进行分析，$max_rows指定了每页显示的最大行数，利用$_GET[$page_holder]获取当前的页号，初始化current_page_number, number_of_rows_per_page, number_of_rows(全部总行数), number_of_pages, sql_query(这个是原来SQL查询语句添加了limit限制的SQL语句)
function splitPageResults($query, $max_rows, $count_key = '*', $page_holder = 'page', $debug = false) {}
// 显示分页链接，$max_page_links指定了显示多少个链接
function display_links($max_page_links, $parameters = '') {}
// 显示分页总数， $text_output传入格式化输出串，方便定制输出
function display_count($text_output) {}
}
分页功能函数详细说明：
<?php
/**
* split_page_results Class.
*
* @package classes
* @copyright Copyright 2003-2009 Zen Cart Development Team
* @copyright Portions Copyright 2003 osCommerce
* @license http://www.zen-cart.com/license/2_0.txt GNU Public License V2.0
* @version $Id: split_page_results.php 17066 2010-07-29 19:18:14Z wilt $
*/
if (!defined('IS_ADMIN_FLAG')) {
die('Illegal Access');
}
/**
* Split Page Result Class
*
* An sql paging class, that allows for sql reslt to be shown over a number of pages using simple navigation system
* Overhaul scheduled for subsequent release
*
* @package classes
*/
class splitPageResults extends base {
var $sql_query, $number_of_rows, $current_page_number, $number_of_pages, $number_of_rows_per_page, $page_name;
/* class constructor */
function splitPageResults($query, $max_rows, $count_key = '*', $page_holder = 'page', $debug = false) {
global $db;
$max_rows = ($max_rows == '' || $max_rows == 0) ? 20 : $max_rows;
$this->sql_query = preg_replace("/\n\r|\r\n|\n|\r/", " ", $query);
$this->page_name = $page_holder;
if ($debug) {
echo 'original_query=' . $query . '<br /><br />';
}
if (isset($_GET[$page_holder])) {
$page = $_GET[$page_holder];
} elseif (isset($_POST[$page_holder])) {
$page = $_POST[$page_holder];
} else {
$page = '';
}
if (empty($page) || !is_numeric($page)) $page = 1;
$this->current_page_number = $page; //当前页码
$this->number_of_rows_per_page = $max_rows; //每页显示数量
$this->sql_query;
$pos_to = strlen($this->sql_query); //895计算sql语句字节总长度
$query_lower = strtolower($this->sql_query);
$pos_from = strpos($query_lower, ' from', 0); //497
$pos_group_by = strpos($query_lower, ' group by', $pos_from);
if (($pos_group_by < $pos_to) && ($pos_group_by != false)) $pos_to = $pos_group_by;
$pos_having = strpos($query_lower, ' having', $pos_from);
if (($pos_having < $pos_to) && ($pos_having != false)) $pos_to = $pos_having;
$pos_order_by = strpos($query_lower, ' order by', $pos_from); //841查询sql语句中sorder by出现的位置，从$pos_form处开始查找
if (($pos_order_by < $pos_to) && ($pos_order_by != false)) $pos_to = $pos_order_by; //841sql语句截取order by之前的部分，用于limit int,int页面查询
if (strpos($query_lower, 'distinct') || strpos($query_lower, 'group by')) {
$count_string = 'distinct ' . zen_db_input($count_key);
} else {
$count_string = zen_db_input($count_key); //* 函数传值，要查询的语句 此处为*
}
$count_query = "select count(" . $count_string . ") as total " .
substr($this->sql_query, $pos_from, ($pos_to - $pos_from)); //查询结果总长度查询语句
if ($debug) {
echo 'count_query=' . $count_query . '<br /><br />';
}
$count = $db->Execute($count_query); //执行结果总数查询
$this->number_of_rows = $count->fields['total']; //查询结果总数160
$this->number_of_pages = ceil($this->number_of_rows / $this->number_of_rows_per_page); //页面总数14
if ($this->current_page_number > $this->number_of_pages) {
$this->current_page_number = $this->number_of_pages;
}
$offset = ($this->number_of_rows_per_page * ($this->current_page_number - 1)); //已经查询的产品数
// fix offset error on some versions
if ($offset <= 0) { $offset = 0; }
$this->sql_query .= " limit " . ($offset > 0 ? $offset . ", " : '') . $this->number_of_rows_per_page; //页面查询语句
}
/* class functions */
// display split-page-number-links
function display_links($max_page_links, $parameters = '') { //$max_page_links导航链接显示的数量，后台控制
global $request_type;
$display_links_string = '';
$class = '';
if (zen_not_null($parameters) && (substr($parameters, -1) != '&')) $parameters .= '&'; //disp_order=6&，若最后一个字符不是& 则替换成&字符
// previous button - not displayed on first page
if ($this->current_page_number > 1) { //若当前页不为第一页，则显示First页面和Previous页面
$display_links_string .= '<a href="' . zen_href_link($_GET['main_page'], $parameters . $this->page_name . '=1', $request_type) . '" title=" ' . PREVNEXT_TITLE_FIRST_PAGE . ' ">' . PREVNEXT_BUTTON_FIRST . '</a> ';
$display_links_string .= '<a href="' . zen_href_link($_GET['main_page'], $parameters . $this->page_name . '=' . ($this->current_page_number - 1), $request_type) . '" title=" ' . PREVNEXT_TITLE_PREVIOUS_PAGE . ' ">' . PREVNEXT_BUTTON_PREV . '</a> ';
}
// check if number_of_pages > $max_page_links
$cur_window_num = intval($this->current_page_number / $max_page_links); //当前循环计数=当前页面/导航链接显示数量取整
if ($this->current_page_number % $max_page_links) $cur_window_num++; //当前循环计数+1
$max_window_num = intval($this->number_of_pages / $max_page_links); //总循环计数页面
if ($this->number_of_pages % $max_page_links) $max_window_num++; //总循环计数页面+1
// previous window of pages
if ($cur_window_num > 1) $display_links_string .= '<a href="' . zen_href_link($_GET['main_page'], $parameters . $this->page_name . '=' . (($cur_window_num - 1) * $max_page_links), $request_type) . '" title=" ' . sprintf(PREVNEXT_TITLE_PREV_SET_OF_NO_PAGE, $max_page_links) . ' ">...</a>'; //显示向前一页循环链接
// page nn button
for ($jump_to_page = 1 + (($cur_window_num - 1) * $max_page_links); ($jump_to_page <= ($cur_window_num * $max_page_links)) && ($jump_to_page <= $this->number_of_pages); $jump_to_page++) { //循环输出页面
if ($jump_to_page == $this->current_page_number) {
$display_links_string .= ' <strong class="current">' . $jump_to_page . '</strong> ';
} else {
$display_links_string .= ' <a href="' . zen_href_link($_GET['main_page'], $parameters . $this->page_name . '=' . $jump_to_page, $request_type) . '" title=" ' . sprintf(PREVNEXT_TITLE_PAGE_NO, $jump_to_page) . ' ">' . $jump_to_page . '</a> ';
}
}
// next window of pages
if ($cur_window_num < $max_window_num) {
$display_links_string .= '<a href="' . zen_href_link($_GET['main_page'], $parameters . $this->page_name . '=' . (($cur_window_num) * $max_page_links + 1), $request_type) . '" title=" ' . sprintf(PREVNEXT_TITLE_NEXT_SET_OF_NO_PAGE, $max_page_links) . ' ">...</a> '; ////显示向后一页循环链接
}
// next button
if (($this->current_page_number < $this->number_of_pages) && ($this->number_of_pages != 1)) { //若当前页不为第一页，则显示Next页面和Last页面
$display_links_string .= ' <a href="' . zen_href_link($_GET['main_page'], $parameters . 'page=' . ($this->current_page_number + 1), $request_type) . '" title=" ' . PREVNEXT_TITLE_NEXT_PAGE . ' ">' . PREVNEXT_BUTTON_NEXT . '</a> ';
$display_links_string .=' <a href="' . zen_href_link($_GET['main_page'], $parameters . 'page=' . $this->number_of_pages, $request_type) . '" title=" ' . PREVNEXT_TITLE_LAST_PAGE . ' ">' . PREVNEXT_BUTTON_LAST . '</a> ';
}
if ($display_links_string == ' <strong class="current">1</strong> ') {
return ' ';
} else {
return $display_links_string;
}
}
// display number of total products found
function display_count($text_output) {
$to_num = ($this->number_of_rows_per_page * $this->current_page_number); //当前页面显示的产品编号
if ($to_num > $this->number_of_rows) $to_num = $this->number_of_rows; //若当前页面计算出来的产品编号大于总的产品数，则取较小值
$from_num = ($this->number_of_rows_per_page * ($this->current_page_number - 1)); //上一页查询结束的产品编号
if ($to_num == 0) {
$from_num = 0;
} else {
$from_num++; //当前页面查询开始产品编号，即上一页查询结束产品编号+1
}
if ($to_num <= 1) {
// don't show count when 1
return '';
} else {
return sprintf($text_output, $from_num, $to_num, $this->number_of_rows); //以传入的字符串格式输出页码参数
}
}
}
?>