Detailed explanation of paging and SqlHelper class usage examples in php

<?php
/**
 * Created by JetBrains PhpStorm.
 * User: lee
 * Date: 13-7-26
 * Time: 下午8:30
 * To change this template use File | Settings | File Templates.
 */
class SqlHelper{
  private $mysqli;
  private static $host="localhost";
  private static $user="root";
  private static $pwd="";
  private static $db="world";
  private $sql=false;
  private $result=false;
  function __construct(){
    $this->mysqli=new MySQLi(self::$host,self::$user,self::$pwd,self::$db);
    if($this->mysqli->connect_error){
      die("连接数据库失败！ ".$this->mysql->connect_error);
    }
    $this->mysqli->query("set names utf8");
  }
  function execute_dql_all($sql){
    //执行查询语句
    $arr=array();
    $this->result=$this->mysqli->query($sql) or die ($this->mysql->connect_error);
    //将数据转存到$arr数组中
    while($row=mysqli_fetch_array($this->result,MYSQL_BOTH)){
      $arr[]=$row;
    }
    $this->result->free();
    return $arr;
  }
  function execute_dql_num($sql){
    //执行查询语句
    $arr=array();
    $this->result=$this->mysqli->query($sql) or die ($this->mysql->connect_error);
    //将数据转存到$arr数组中
    while($row=mysqli_fetch_array($this->result,MYSQLI_NUM)){
      $arr[]=$row;
    }
    $this->result->free();
    return $arr;
  }
  function execute_dql_assoc($sql){
    //执行查询语句
    $arr=array();
    $this->result=$this->mysqli->query($sql) or die ($this->mysql->connect_error);
    //将数据转存到$arr数组中
    while($row=mysqli_fetch_array($this->result,MYSQLI_ASSOC)){
      $arr[]=$row;
    }
    $this->result->free();
    return $arr;
  }
  //查询某表中的记录数
  function execute_dql_counts($table,$id="*"){
    $this->sql="select count($id) from $table";
    $this->result=$this->mysqli->query($this->sql);
    $row=mysqli_fetch_all($this->result);
    $this->result->free();
    return $row[0][0];
  }
  function execute_dml($sql){
    //执行正删改
    $this->result=$this->mysqli->query($sql);
    if(!$this->result){
      return -1;//执行正删改失败
    }else{
      if($this->mysqli->affected_rows>0){
        return 1;//执行正删改成功，影响行数
      }else{
        return 0;//执行正删改成功，但没有影响行数
      }
    }
  }
}

<?php
/**
 * Created by JetBrains PhpStorm.
 * User: lee
 * Date: 13-7-27
 * Time: 下午2:48
 * To change this template use File | Settings | File Templates.
 */
header("Content-type:text/html;charset=utf-8;");
require_once("SqlHelper.php");
class Paging {
  private $sqlHelper=false;
  private $pageCount=false;//页数
  private $counts=false;//总记录数
  private $returnArr=false;//分页超链接的分页
  function __construct(){
    $this->sqlHelper=new SqlHelper();
    $this->returnArr=array();
  }
  /*
   * 参数说明
   *
   * $table 分页时对那个表的数据分页
   * $id 辅助查询当前分页的数据表的总记录数
   * $pageSize 每页显示多少条信息记录数
   * $pagingSize 分页栏每次循环显示出来的个数
   * $nowPage 当前是第几页，默认第一页
   * $href 分页栏的超链接将要往哪里连接
   */
  function paging_prev_next($table,$id="*",$pageSize,$pagingSize,$nowPage=1,$href){
    $this->counts=$this->sqlHelper->execute_dql_counts($table,$id);
    $this->pageCount=ceil($this->counts/$pageSize);
    $this->returnArr["count"]=$this->counts;
    $this->returnArr["start"]=($nowPage-1)*$pageSize;
    $this->returnArr["limit"]=$pageSize;
    if($nowPage>$this->pageCount || $nowPage<=0){
      return false;
    }
    $t=(ceil($nowPage/$pagingSize)-1)*$pagingSize+1;
    $pre=$nowPage-$pagingSize;
    $nex=$nowPage+$pagingSize;
    echo "
      <span class=&#39;paging-list-a paging-list-a-withBg&#39;>{$nowPage}/{$this->pageCount}</span>
      <a href=&#39;{$href}?nowPage={$pre}&#39; class=&#39;paging-list-a&#39;><</a>";
    for($i=$t;$i<$t+$pagingSize;$i++){
      if($i*$pageSize>$this->pageCount*$pageSize){
        break;
      }else{
        if($nowPage==$i){
          echo "
          <a href=&#39;{$href}?nowPage={$i}&#39; class=&#39;paging-list-a paging-list-a-withBg&#39;>{$i}</a>";
        }else{
          echo "
          <a href=&#39;{$href}?nowPage={$i}&#39; class=&#39;paging-list-a&#39;>{$i}</a>";
        }
      }
    }
    echo "
      <a href=&#39;{$href}?nowPage={$nex}&#39; class=&#39;paging-list-a&#39;>></a>";
    return $this->returnArr;
  }
}

/**
 * Created by JetBrains PhpStorm.
 * User: lee
 * Date: 13-7-27
 * Time: 下午5:56
 * To change this template use File | Settings | File Templates.
 */
.paging-list-a{
  border:1px solid #b5b5af;
  background-color:#efebed;
  font-family: 'Meiryo UI';
  font-size: 16px;
  font-weight: 600;
  padding: 0px 8px 0px 8px;
  /*cursor: pointer;*/
  text-decoration: none;
  color: #292927;
}
.paging-list-a-withBg{
  background-color: #1D92E2;
  color: white;
}

<!DOCTYPE html>
<html>
<head>
  <title></title>
  <link rel="stylesheet" type="text/css" href="paging-list-link.css">
</head>
<body>
<?php
header("Content-type:text/html;charset=utf-8;");
require_once &#39;Paging.php&#39;;
$paging=new Paging();
//参数说明
/*
 * $table 分页时对那个表的数据分页
 * $id 辅助查询当前分页的数据表的总记录数
 * $pageSize 每页显示多少条信息记录数
 * $pagingSize 分页栏每次循环显示出来的个数
 * $nowPage 当前是第几页，默认第一页
 * $href 分页栏的超链接将要往哪里连接，当前页链接地址
 */
//控制起始页为
$nowPage=1;
if(isset($_GET["nowPage"])){
  $nowPage=$_GET["nowPage"];
}
//定义分页所需参数
$meiyexiansi=10;
$meiyelianjieshu=10;
$receiveArr=array();
$receiveArr=$paging->paging_prev_next("city","ID",$meiyexiansi,$meiyelianjieshu,$nowPage,"usePaging.php");
//容错判断
if(!$receiveArr){
  return;
}
//查询每页需要显示的数据，大小限制存在 $receiveArr 数组中
$sqlHelper=new SqlHelper();
$result=$sqlHelper->execute_dql_num("select * from city limit ".$receiveArr[&#39;start&#39;].",".$receiveArr[&#39;limit&#39;]."");
echo "<pre class="brush:php;toolbar:false">";
print_r($result);
echo "

if($nowPage>$this->pageCount || $nowPage<=0){
  return false;
}