复制代码 代码如下:
<?php
header("content-type:text/html;charset=utf-8");
//数据库连接
$conn = mysql_connect("localhost", "root", "111") or die("not connnected : ".mysql_error());
mysql_select_db("test", $conn);
mysql_query("set names utf8");

//查询共有多少行数据
$sql1 = "select count(*) from user";
$ret1 = mysql_query($sql1);
$row1 = mysql_fetch_row($ret1);
$tot = $row1[0];

//每页多少行数据
$length = 5;
//总页数
$totpage = ceil($tot / $length);

//当前页数
$page = @$_GET['p'] ? $_GET['p'] : 1;
//limit 下限
$offset = ($page - 1) * $length;

echo "<center>";
echo "<h2>php padding</h2>";
echo "<table width='700px' border='1px' >";
echo "<tr>";
echo "<th>ID</th>";
echo "<th>USER</th>";
echo "<th>PASS</th>";
echo "</tr>";

//将查询出来的数据用表格显示
$sql2 = "select * from user order by id limit {$offset}, {$length}";
$ret2 = mysql_query($sql2);
while ($row2 = mysql_fetch_assoc($ret2)) {
echo "<tr>";
echo "<td>{$row2['id']}</td><td>{$row2['name']}</td><td>{$row2['pass']}</td>";
echo "</tr>";
}

echo "</table>";

//上一页和下一页
$prevpage = $page - 1;
if ($page >= $totpage) {
$nextpage = $totpage;
} else {
$nextpage = $page + 1;
}

//跳转
echo "<h3><a href='index.php?p={$prevpage}'>上一页</a>|<a href='index.php?p={$nextpage}'>下一页</a></h3>";
echo "</center>";

核心点：

<1>“$sql2 = "select * from user order by id limit {$offset}, {$length}";”，$offset、$length和页数之间的关系。

<2>上一页和下一页的获得方式，以及临界点。