自己编写的php+mysql实现新闻系统中“上一条”，“下一条”的简单程序
我也是个PHP新手，最近在做一个网站的新闻发布系统中，需要用到“上一条””下一条“这样的效果，就自己编写一个，由于是新手，不足之处，还望高手指正。
$colname_rs = "-1";if (isset($_GET['id'])) { $colname_rs = $_GET['id'];}mysql_select_db($database_conn, $conn);$query_rs = sprintf("SELECT * FROM news WHERE id = %s", GetSQLValueString($colname_rs, "int"));$rs = mysql_query($query_rs, $conn) or die(mysql_error());$row_rs = mysql_fetch_assoc($rs);$totalRows_rs = mysql_num_rows($rs);$next_sql="SELECT * FROM news WHERE id >$colname_rs ORDER BY id ASC LIMIT 1 ";$rsnext= mysql_query($next_sql, $conn) or die(mysql_error());$row_next = mysql_fetch_assoc($rsnext);$prev_sql="SELECT * FROM news WHERE id <$colname_rs ORDER BY id DESC LIMIT 1 ";$rsprev= mysql_query($prev_sql, $conn) or die(mysql_error());$row_prev = mysql_fetch_assoc($rsprev);$max_sql="SELECT MAX(id) FROM news";$rsmax = mysql_query($max_sql, $conn) or die(mysql_error());$row_max = mysql_fetch_array($rsmax);$min_sql="SELECT MIN(id) FROM news";$rsmin = mysql_query($min_sql, $conn) or die(mysql_error());$row_min = mysql_fetch_array($rsmin);$min_id=mysql_result($rsmin,0);$max_id=mysql_result($rsmax,0);switch ($colname_rs){case $min_id :$ptext="没有了";$ntext= "<a href="index.php?id=".$row_next['id']."">".$row_next['tiltle']."</a>"; break;case $max_id:$ptext= "<a href="index.php?id=".$row_prev['id']."">".$row_prev['tiltle']."</a>";$ntext="没有了"; break;default:$ptext= "<a href="index.php?id=".$row_prev['id']."">".$row_prev['tiltle']."</a>";$ntext= "<a href="index.php?id=".$row_next['id']."">".$row_next['tiltle']."</a>";}<?php echo $ptext; ?>
<?php echo $ntext; ?>