Preliminary exploration of PHP paging A simple implementation of the simplest PHP paging code, preliminary exploration of paging

PHP paging code must be used in various program development, on the website It is a must-select during development.

To write paging code, you must first understand the SQL query statement: select * from goods limit 2,7. The core of the PHP paging code revolves around this statement. The SQL statement explains: Query the goods data table and retrieve 7 pieces of data starting from the 2nd piece of data. In the paging code, 7 represents how many pieces of content are displayed on each page, and 2 represents the number of page turns calculated by a formula. By replacing the value of "2" with different parameters, you can filter out different data.

index.php:

include 'conn.php';　　//引入數(shù)據(jù)庫操作類 
 
$conn=new conn();　　//實例化數(shù)據(jù)庫操作類 
 
$total=$conn->getOne('select count(*) as total from goods'); 
$total=$total['total']; //goods表數(shù)據(jù)總數(shù)據(jù)條數(shù) 
$num=6; //每頁顯示條數(shù) 
$totalpage=ceil($total/$num);  //計算頁數(shù) 
if(isset($_GET['page']) && $_GET['page']<=$totalpage){//這里做了一個判斷，若get到數(shù)據(jù)并且該數(shù)據(jù)小于總頁數(shù)情況下才付給當(dāng)前頁參數(shù)，否則跳轉(zhuǎn)到第一頁 
  $thispage=$_GET['page']; 
}else{ 
  $thispage=1; 
} 
<BR>//注意下面sql語句中紅色部分，通過計算來確定從第幾條數(shù)據(jù)開始取出，當(dāng)前頁數(shù)減去1后再乘以每頁顯示數(shù)據(jù)條數(shù) 
$sql='select goods_id,goods_name,shop_price from goods order by goods_id limit '.<SPAN style="COLOR: #ff0000">($thispage-1)*$num</SPAN>.','.$num.''; 
 
$data=$conn->getAll($sql); 
 
foreach($data as $k=>$v){ 
  echo '<li>'.$v['goods_id'].'、'.$v['goods_name'].'---￥'.$v['shop_price'].'</li>';   
} 
<BR>//顯示分頁數(shù)字列表 
for($i=1;$i<=$totalpage;$i++){ 
  echo '<a href="&#63;page='.$i.'">'.$i.'</a> ';  
   
}

The above code implements the simplest PHP paging effect:

Only click on the page turning number to display different page turning data. It can be further improved on this basis. As long as the basic principles are understood, subsequent work will be easier to develop.

conn.php code:

/* 
*連接數(shù)據(jù)庫 進行相關(guān)查詢操作 
*/
 
class conn{ 
 
  public function __construct(){ 
    include_once('config.php'); 
    try{   
      $this->pdo = new PDO('mysql:host=localhost;dbname=test', 'root', '123456'); 
      $this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); 
      $this->pdo->exec('set names utf8'); 
       
 
    }catch(PDOException $e){ 
      echo '數(shù)據(jù)庫連接失敗:'.$e->getMessage(); 
      exit(); 
    } 
  } 
   
  //獲取一行數(shù)據(jù) 
  public function getOne($sql){ 
    $rs=$this->pdo->query($sql)->fetch(PDO::FETCH_ASSOC); 
     
    return $rs; 
  } 
   
  //獲取多行數(shù)據(jù)結(jié)果 
  public function getAll($sql){ 
    $rs=$this->pdo->query($sql)->fetchall(PDO::FETCH_ASSOC); 
     
    return $rs; 
 
  } 
}

The function of conn.php is to complete the database connection and implement the data extraction operation method. Here I am using pdo. The code can be organized according to everyone's habits.

config.php:

* 
*配置數(shù)據(jù)庫信息 
*/
 
$cfg_dbhost='localhost'; 
$cfg_dbname='test'; 
$cfg_dbuser='root'; 
$cfg_dbpw='123456'; 

This example is only to illustrate the basic paging principle, and there are still many modifications before it can be used in practice.

The above is the initial exploration of PHP paging brought to you by the editor. A simple implementation of the simplest PHP paging code. I hope you like it~

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