How to implement paging function in PHP

PHP is one of the most popular dynamic web programming languages. It is a high-level scripting language used to create dynamic web sites. When designing web applications, paging functionality is often required so that users can easily browse and view data when the amount of data is huge. This article will introduce how to implement paging function in PHP.

1. Determine the number of records displayed on each page

Before implementing the paging function, you first need to clarify the number of records that need to be displayed on each page. Normally, the number of records displayed on each page is generally 10 or 20. After determining the number of records that need to be displayed on each page, the number of pages can be calculated based on the total amount of data.

2. Calculate the total number of pages

To calculate the total number of pages, you need to use the total amount of data and the number of records to be displayed on each page. The calculation formula is as follows:

$pages = ceil($total/$per_page);

Among them, $total represents the total amount of data, $per_page represents the number of records that need to be displayed on each page, and ceil() is the upward rounding function. The calculated $pages variable represents the total number of pages.

3. Get the current page number and corresponding records

In the process of implementing the paging function, you also need to obtain the page number of the current page and obtain the corresponding record from the database or other data sources recorded data. The current page number can be obtained through GET or POST method. The relevant code is as follows:

$page = isset($_GET['page']) ? (int)$_GET['page'] : 1;

Among them, the isset() function is used to detect whether $page exists. If it exists, the value is converted to an integer type. If it does not exist, it defaults to 1.

After that, you need to obtain the corresponding record data from the database or other data sources based on the current page number and the number of records that need to be displayed on each page. The relevant code is as follows:

$start = ($page - 1) * $per_page;
$sql = "SELECT * FROM tablename LIMIT $start,$per_page";
$result = mysqli_query( $conn, $sql);

Among them, $start represents the starting recording position of each page, $sql represents the SQL statement to obtain data from the data source, and $result is the obtained data result set.

4. Display paging links

After obtaining the current page number and corresponding record data, paging links need to be displayed to allow users to browse and jump to other pages conveniently . Displaying paging links can be achieved by displaying page numbers in a loop. The relevant code is as follows:

for ($i = 1; $i <= $pages; $i ) {
echo "$i " ;
}