分页原理是什么
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2022-04-03 15:19:52
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数据分页需要以下几个条件：
1. 参与分页的总条数 【$msg_count】 ，该值通过数据库查询可以获取到;
2. 每页显示的条数【$pagesize】 ，这个数值由自己定义;
3. 当前页的页码数 【$page】，该数值通过地址栏传递和接收；
4. 可以通过以上资料计算出总页数 【$pagecount】 ，此处需要借助ceil();
【$pagecount = ceil($msg_count/$pagesize);】
5. 数据库查询借助sql语句中的【limit】来实现数据的变化：
例如：
select * from 表名 where 条件 limit $startnum , $pagesize;
而$startnum = ($page-1)*$pagesize;
实例：
/**
* 取得上次的过滤条件
* @param string $param_str 参数字符串，由list函数的参数组成
* @return 如果有，返回array('filter' => $filter, 'sql' => $sql)；否则返回false
*/
function get_filter($param_str = '')
{
$filterfile = basename(PHP_SELF, '.php');//string basename ( string $path [, string $suffix ] ) 返回路径中的文件名部分如果文件名是以 suffix 结束的，那这一部分也会被去掉。
if ($param_str)
{
$filterfile .= $param_str;
}
if (isset($_GET['uselastfilter']) && isset($_COOKIE['ECSCP']['lastfilterfile'])
&& $_COOKIE['ECSCP']['lastfilterfile'] == sprintf('%X', crc32($filterfile)))
{
return array(
'filter' => unserialize(urldecode($_COOKIE['ECSCP']['lastfilter'])),
'sql' => base64_decode($_COOKIE['ECSCP']['lastfiltersql'])
);
}
else
{
return false;
}
}
/**
* 保存过滤条件
* @param array $filter 过滤条件
* @param string $sql 查询语句
* @param string $param_str 参数字符串，由list函数的参数组成
*/
function set_filter($filter, $sql, $param_str = '')
{
$filterfile = basename(PHP_SELF, '.php');
if ($param_str)
{
$filterfile .= $param_str;
}
setcookie('ECSCP[lastfilterfile]', sprintf('%X', crc32($filterfile)), time() + 600);
setcookie('ECSCP[lastfilter]', urlencode(serialize($filter)), time() + 600);
setcookie('ECSCP[lastfiltersql]', base64_encode($sql), time() + 600);
}
/**
* 供货商资源管理
* @param bool $is_pagtion
* @return array $arr
*/
function suppliers_resource_manage($is_pagtion=true)
{
global $db,$ecs;
$result = get_filter();
if ($result === false)
{
$aiax = isset($_GET['is_ajax']) ? $_GET['is_ajax'] : 0;
/* 过滤信息 */
$filter['sort_by'] = empty($_REQUEST['sort_by']) ? 'r.resource_id' : trim($_REQUEST['sort_by']);
$filter['sort_order'] = empty($_REQUEST['sort_order']) ? 'DESC' : trim($_REQUEST['sort_order']);
$filter['resource_id'] = empty($_REQUEST['resource_id']) ? '' : $_REQUEST['resource_id'];
$filter['admin_name'] = empty($_REQUEST['admin_name']) ? '' : trim($_REQUEST['admin_name']);
$filter['resource_name'] = empty($_REQUEST['resource_name']) ? '' : trim($_REQUEST['resource_name']);
$filter['admin_id'] = isset($_REQUEST['admin_id'])?intval($_REQUEST['admin_id']):'-1';
$filter['resource_type'] = empty($_REQUEST['resource_type']) ? '-1' : intval($_REQUEST['resource_type']);
$filter['resource_status'] = empty($_REQUEST['resource_status']) ? '-1' : intval($_REQUEST['resource_status']);
$filter['resource_rank'] = empty($_REQUEST['resource_rank']) ? '-1' : intval($_REQUEST['resource_rank']);
$filter['resource_key'] = empty($_REQUEST['resource_key']) ? '' : trim($_REQUEST['resource_key']);
$filter['menuid'] = 7;
$where = 'WHERE 1 ';
/* 分页大小 */
$filter['page'] = empty($_REQUEST['page']) || (intval($_REQUEST['page']) <= 0) ? 1 : intval($_REQUEST['page']);
if (isset($_REQUEST['page_size']) && intval($_REQUEST['page_size']) > 0)
{
$filter['page_size'] = intval($_REQUEST['page_size']);
}
elseif (isset($_COOKIE['ECSCP']['page_size']) && intval($_COOKIE['ECSCP']['page_size']) > 0)
{
$filter['page_size'] = intval($_COOKIE['ECSCP']['page_size']);
}
else
{
$filter['page_size'] = 15;
}
if(!empty($filter['resource_id']))
{
$resource_id = $filter['resource_id'] == -1 ? 0 : $filter['resource_id'];
$where .= " and r.resource_id='".$resource_id."'";
}
if($filter['resource_name']){
$where .= " AND r.resource_name like '%".mysql_like_quote($filter['resource_name'])."%' ";
}
if($filter['admin_id'] > -1)
{
$where .= " AND r.admin_id = '".$filter['admin_id']."' ";
}
if ($filter['resource_type'] > -1)
{
$where .= " AND r.resource_type = '" . $filter['resource_type'] . "'";
}
if ($filter['resource_status'] > -1)
{
$where .= " AND r.resource_status = '" . $filter['resource_status'] . "'";
}
if ($filter['resource_rank'] > -1)
{
$where .= " AND r.resource_rank = '" . $filter['resource_rank'] . "'";
}
if($filter['resource_key']){
$where .= " AND r.remark like '%".mysql_like_quote($filter['resource_key'])."%' ";
}
/* 记录总数 */
$sql = "SELECT COUNT(r.resource_id) FROM " . $ecs->table('suppliers_resource')." as r
LEFT JOIN ".$ecs->table('admin_user') . " as u
ON u.user_id = r.admin_id " . $where;
$filter['record_count'] = $db->getOne($sql);
$filter['page_count'] = $filter['record_count'] > 0 ? ceil($filter['record_count'] / $filter['page_size']) : 1;
/* 查询 */
$sql = "SELECT r.resource_id, u.user_name as admin_name, r.resource_name, r.resource_link, r.resource_type, r.resource_status, r.resource_rank, r.remark, r.add_time FROM " . $ecs->table('suppliers_resource') . " as r
LEFT JOIN " . $ecs->table('admin_user') . " as u ON u.user_id = r.admin_id " . $where;
$sort_by = $filter['sort_by'];
$sort_order = $filter['sort_order'];
$sql .="GROUP BY r.resource_id ORDER BY " . $sort_by . " " . $sort_order;
if($is_pagtion)
{
$sql .=" LIMIT ".($filter['page'] - 1)*$filter['page_size'].",".$filter['page_size'];
}
set_filter($filter, $sql);
}
else
{
$sql = $result['sql'];
$filter = $result['filter'];
}
$query=$sql;
$row = $db->getAll($sql);
/* 格式话数据 */
foreach ($row AS $key => $value)
{
if ($row[$key]['resource_type'] == 1) {
$row[$key]['resource_type'] = '中模';
}elseif ($row[$key]['resource_type'] == 2) {
$row[$key]['resource_type'] = '泳装';
}elseif ($row[$key]['resource_type'] == 3) {
$row[$key]['resource_type'] = '阿里';
}elseif ($row[$key]['resource_type'] == 2) {
$row[$key]['resource_type'] = '17网';
}
if ($row[$key]['resource_status'] == 1) {
$row[$key]['resource_status'] = '已审核';
}elseif ($row[$key]['resource_status'] == 2) {
$row[$key]['resource_status'] = '已弃用';
}
if ($row[$key]['resource_rank'] == 1)
{
$row[$key]['resource_rank'] = 'A';
}elseif ($row[$key]['resource_rank'] == 2) {
$row[$key]['resource_rank'] = 'B';
}elseif ($row[$key]['resource_rank'] == 3) {
$row[$key]['resource_rank'] = 'C';
}
if(strpos($row[$key]['resource_link'], 'http://') === false)
{
if (strpos($row[$key]['resource_link'], 'https://') === false)
{
$row[$key]['resource_link'] = substr_replace($row[$key]['resource_link'], 'http://', 0, 0);
}
}
}
$arr = array('result' => $row, 'filter' => $filter, 'page_count' => $filter['page_count'], 'record_count' => $filter['record_count'],'query'=>$query);
return $arr;
}
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