PHP实现分页

php分页操作演示

page.php代码

<?php
namespace _0819;
use PDO;
// 连接
$db = new PDO('mysql:dbname=phpedu', 'root', 'root');
// 1. 页数
$page = $_GET['p'] ?? 1;
echo '当前页数: p = ' . $page . '<br>';
// 2. 数量
$num = 5;
echo '当前数量: num = ' . $num . '<br>';
// 3. 偏移量 = (页数 - 1) * 数量
$offset = ($page - 1) * $num;
echo '当前偏移量: offset = ' . $offset . '<br>';
// 4. 计算总记录数
// SELECT CEIL(COUNT(*)/5) AS `total` FROM `staff`
// SELECT COUNT(*) AS `total` FROM `staff`
$sql = 'SELECT COUNT(*) AS `total` FROM `staff`';
$stmt = $db->prepare($sql);
$stmt->execute();
// 将总数量绑定到一个变量上
$stmt->bindColumn('total', $total);
$stmt->fetch();
echo '当前总记录数量: total = ' . $total . '<br>';
// 5. 计算总页数
// 向上取整
$pages = ceil($total / $num);
echo '当前总页数: pages = ' . $pages . '<br>';
$sql = <<< SQL
    SELECT *
    FROM `staff`
    LIMIT $offset, $num;
SQL;
$stmt = $db->prepare($sql);
$stmt->execute();
$staffs = $stmt->fetchAll(PDO::FETCH_ASSOC);
echo '<hr>';
/**
 * 生成分页码
 *
 * @param integer $page 当前页
 * @param integer $pages 总页数
 * @return array
 */
// function createPages(int $page, int $pages): array
// {
// 当前是第8页, 共计20页
// [1,  ...    6, 7, 8, 9, 10,  ....    20]
// 当前是第10页, 共计20页
// [1,  ...    8, 9, 10, 11, 12,  ....    20]
// 1. 生成与总页数长度相同的递增的整数数组
$pageArr = range(1, $pages);
// 2. 只需要当前和前后二页, 其它页码用 false/null 来标记
$paginate =  array_map(function ($p) use ($page, $pages) {
    return ($p == 1 || $p == $pages || abs($page - $p) <= 2) ? $p : null;
}, $pageArr);
// dump($paginate);
// 去重, 替换
$before = array_unique(array_slice($paginate, 0, $page));
$after = array_unique(array_slice($paginate, $page));
// 用解构进行合并
// return   [...$before, ...$after];
$page_ret =  [...$before, ...$after];
// }

<?php
require 'page.php';
?>
<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>PHP实现分页</title>
</head>
<style>
    table {
        width: 400px;
        border-collapse: collapse;
        text-align: center;
    }
    table th,
    table td {
        border: 1px solid;
        padding: 5px;
    }
    table thead {
        background-color: lightcyan;
    }
    table caption {
        font-size: larger;
        margin-bottom: 8px;
    }
    body>p {
        display: flex;
    }
    p>a {
        text-decoration: none;
        color: #555;
        border: 1px solid;
        padding: 5px 10px;
        margin: 10px 2px;
    }
    .active {
        background-color: seagreen;
        color: white;
        border: 1px solid seagreen;
    }
</style>
<body>
    <table>
        <caption>员工信息表</caption>
        <thead>
            <tr>
                <th>ID</th>
                <th>姓名</th>
                <th>性别</th>
                <th>邮箱</th>
            </tr>
        </thead>
        <tbody>
            <?php foreach ($staffs as $staff) : extract($staff) ?>
                <?php $sex = $sex ? '男' : '女';
                ?>
                <tr>
                    <td><?= $id ?>
                    </td>
                    <td><?= $name ?>
                    </td>
                    <td><?= $sex ?>
                    </td>
                    <td><?= $email ?>
                    </td>
                </tr>
            <?php endforeach ?>
        </tbody>
    </table>
    <p>
        <?php
        $a = $page - 1;
        if ($page <= 0) {
            echo "<script>alert('前面没有了');history.go(-1);</script>";
            $a = 1;
        }
        $dqpage = $_SERVER['PHP_SELF'] . '?p=' . $a;
        ?>
        <a href="<?= $dqpage ?>">上一页</a>
        <?php foreach ($page_ret as $k => $v) : ?>
            <?php
            // 页码跳转的url
            if ($v === null) {
                $v = '...';
            }
            if ($v === '...') {
                $url = '#';
            } else {
                $url =  $_SERVER['PHP_SELF'] . '?p=' . $v;
            }
            // 实现页码高亮
            $page = $_GET['p'] ?? 1;
            $active = ($v == $page) ? 'active' : null;
            ?>
            <a href="<?= $url ?>" class="<?= $active ?>"><?= $v ?></a>
        <?php endforeach ?>
        <?php
        $b = $page + 1;
        if ($page > $pages) {
            echo "<script>alert('后面没有了');history.go(-1);</script>";
            $a = $pages;
        }
        $dqpage = $_SERVER['PHP_SELF'] . '?p=' . $b;
        ?>
        <a href="<?= $dqpage ?>">下一页</a>
    </p>
</body>
</html>

php分页操作演示

page.php代码

运行效果

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