php分页代码实例有注释

2. header("content-type:text/html;charset=utf-8");
3. //数据库连接
4. $conn = mysql_connect("localhost", "root", "111") or die("not connnected : ".mysql_error());
5. mysql_select_db("test", $conn);
6. mysql_query("set names utf8");
7. //查询共有多少行数据
8. $sql1 = "select count(*) from user";
9. $ret1 = mysql_query($sql1);
10. $row1 = mysql_fetch_row($ret1);
11. $tot = $row1[0];
12. //每页多少行数据
13. $length = 5;
14. //总页数
15. $totpage = ceil($tot / $length);
16. //当前页数
17. $page = @$_GET['p'] ? $_GET['p'] : 1;
18. //limit 下限
19. $offset = ($page - 1) * $length;
20. echo "";
    echo "

    php padding

    ";
    echo "";
    echo "
    ";
    echo "
    ";
    echo "
    ";
    echo "
    ";
    echo "
    ";
    //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 "
    ";
    echo "
    ";
    echo "
    ";
    }
    echo "

    ID	USER	PASS
    {$row2['id']}	{$row2['name']}	{$row2['pass']}

    ";
21. //上一页和下一页
22. $prevpage = $page - 1;
23. if ($page >= $totpage) {
24. $nextpage = $totpage;
25. } else {
26. $nextpage = $page + 1;
27. }
28. //跳转
29. echo "

    上一页|下一页

    ";
30. echo "
";

复制代码

分页代码关键点： “$sql2 = "select * from user order by id limit {$offset}, {$length}";”，$offset、$length和页数之间的关系。 上一页和下一页的获得方式，以及临界点。