counter.php

网上书店网站系统

<?php
function counter($id)
{
	session_start();
	if(session_is_registered("count")==false)
	{
		session_register("count");
	}
	else
	{
		return $count;
	}

$db=@mysql_connect("localhost","root","307910");
if($db==false)
{
	print "Connect to localhost failed!";
	exit();
}
$res=@mysql_select_db("bookseller",$db);
if($res==false)
{
	print "Use database test failed!";
	exit();
}
$query="select counter from counter where id=$id;";
$res=mysql_query($query,$db);
if($res==false)
{
	print "query failed!";
	exit();
}
$row=mysql_fetch_row($res);
if($row==false)
{
	print "id $id doesn't exist!";
	exit();
}
$count=$row[0]+1;
$query="update counter set counter=$count where id=$id";
$res=mysql_query($query,$db);
if($res==false)
{
	print "update failed!";
	exit();
}
mysql_close($db);
return $count;
}

?>