即使你没有被调用，函数也会运行

Question

I'm looking for a way to clean my DB with a button on a html-page (.php). I have a code that's working OK, but every time I go in to the page the function is cleaning my DB without me pushing the button.

Here is my code

<button id="checkoutbutton" onclick="cleanDb()">Clean DB</button>
<script>
function cleanDb()
{alert("<?php clean();?>")}
</script>
<?php
function clean()
{
 $con=mysql_connect("localhost","rss","Habb0") or die("Failed to connect to MySQL: " . mysql_error());
 $db=mysql_select_db("kalender",$con) or die("Failed to connect to MySQL: " . mysql_error());
 $sql='DELETE FROM `bilder` WHERE `stop` < now()';
 mysql_query($sql);

 echo "Databasen är rensad från gamla bilder";}
?>

Please help me!

Answer 1

PHP is parsed on the server side, JavaScript is parsed on the client side. Any PHP operation will run first, before any javascript (Not considering AJAX).