PHP implements paging display code

The so-called paging display means that the result set in the database is artificially divided into sections for display. Two initial parameters are required here:

How many per page Records($PageSize)?

What page is the current page ($CurrentPageID)?

Now as long as you give me another result set, I can display a specific result.
As for other parameters, such as: Previous page ($PReviousPageID) , Next page ($NextPageID) , Total number of pages ($numPages ), etc., can be obtained based on previous knowledge.

Take MySQL database as an example. If you want to intercept a certain piece of content from the table, the sql statement can be used: select * from table limit offset, rows. Take a look at the following set of SQL statements and try to find the rules.

The first 10 records: select * from table limit 0,10

The 11th to 20th records: select * from table limit 10,10

Records 21 to 30: select * from table limit 20,10

……

This set of sql statements is actually the sql statement for fetching data from each page of the table when $PageSize=10. We can summarize such a template:

select * from table limit ($CurrentPageID - 1) * $PageSize, $PageSize

Use this template to substitute the corresponding Compare the value with the above set of SQL statements to see if that is the case. After solving the most important problem of how to obtain the data, all that is left is to pass the parameters, construct the appropriate SQL statement and then use PHP to obtain the data from the database and display it. Below I will explain it with specific code.
Simple code implementation
Please read the following code in detail, debug and run it yourself. It is best to modify it once and add your own functions, such as search, etc.

// 建立数据库连接 
$link = mysql_connect("localhost", "mysql_user", "mysql_passWord")  
   or die("Could not connect: " . mysql_error());  
// 获取当前页数 
if( isset($_GET['page']) ){ 
  $page = intval( $_GET['page'] ); 
} 
else{ 
  $page = 1; 
}  
// 每页数量 
$PageSize = 10;  
// 获取总数据量 
$sql = "select count(*) as amount from table"; 
$result = mysql_query($sql); 
$row = mysql_fetch_row($result); 
$amount = $row['amount'];  
// 记算总共有多少页 
if( $amount ){ 
  if( $amount < $page_size ){ $page_count = 1; }        //如果总数据量小于$PageSize，那么只有一页 
  if( $amount % $page_size ){                 //取总数据量除以每页数的余数 
    $page_count = (int)($amount / $page_size) + 1;      //如果有余数，则页数等于总数据量除以每页数的结果取整再加一 
  }else{ 
    $page_count = $amount / $page_size;           //如果没有余数，则页数等于总数据量除以每页数的结果 
  } 
} 
else{ 
  $page_count = 0; 
} 
// 翻页链接 
$page_string = &#39;&#39;; 
if( $page == 1 ){ 
  $page_string .= &#39;第一页|上一页|&#39;; 
} 
else{ 
  $page_string .= &#39;第一页|.($page-1).&#39;>上一页|&#39;; 
}  
if( ($page == $page_count) || ($page_count == 0) ){ 
  $page_string .= &#39;下一页|尾页&#39;; 
} 
else{ 
  $page_string .= &#39;.($page+1).&#39;>下一页|.$page_count.&#39;>尾页&#39;; 
} 
// 获取数据，以二维数组格式返回结果 
if( $amount ){ 
  $sql = "select * from table order by id desc limit ". ($page-1)*$page_size .", $page_size"; 
  $result = mysql_query($sql); 
  while ( $row = mysql_fetch_row($result) ){ 
    $rowset[] = $row; 
  } 
}else{ 
  $rowset = array(); 
} 
// 没有包含显示结果的代码，那不在讨论范围，只要用foreach就可以很简单的用得到的二维数组来显示结果 
?>

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