【php】php面向对象入门级别的类

来源：互联网发布：windows开机配置失败编辑：程序博客网时间：2024/05/10 12:54

<?php

class Dao {

function __construct() {
  mysql_connect('localhost','root','');
  mysql_select_db('test');
  mysql_query('set names utf8');
}

/**
* 分页查询
*/
function page($sql) {

  $page = $_GET['page'];
  $page = intval($page);
  if($page <= 0) {
   $page = 1;
  }

  //取有多少页
  $itemNumSql = 'select count(*) num '.strstr($sql,'from');
  $itemNums = $this->queryOne($itemNumSql);
  $itemNum = $itemNums['num'];
  $countPage = ceil($itemNum/10);

  if($page > $countPage) {
   $page = $countPage;
  }

  //取当前页所有数据
  $sn = ($page-1)*10;
  $sql = $sql." limit $sn,10";
  $r = mysql_query($sql);
  while($a = mysql_fetch_assoc($r))
  {
   $ret[] = $a;
  }

  $pinfo = "共{$itemNum}条{$countPage}页当前第{$page}页 <a href='?page=1'>首页</a> ".
   "<a href='?page=".($page-1)."'>上一页</a> ".
   "<a href='?page=".($page == $countPage ? $page : $page+1)."'>下一页</a> ".
   "<a href='?page=$countPage'>末页</a>";
  $a = array('item'=>$ret,'page'=>$pinfo);
  return $a;
}

/**
*取一条数据
*/
function queryOne($sql) {
  $r = mysql_query($sql.' limit 1');
  $a = mysql_fetch_assoc($r);
  return $a;
}

/**
* 检索所有数据
*/
function query($sql) {

  $r = mysql_query($sql);
  while($a = mysql_fetch_assoc($r))
  {
   $ret[] = $a;
  }

return $ret;
}

/**
*插入数据
*/
function insert($sql) {
  mysql_query($sql);
  return mysql_insert_id();
}

/**
*更新
*/
function update($sql) {
  $num = mysql_query($sql);
  return $num;
}
}