If mysql_num_rows equals to ZERO is NOT working

I'm using this code to count rows and trying to do IF num rows equals to ZERO do INSERT if not UPDATE but it doesn't work.

When I use == operator nothing happens. If I use >= operator script inserting the values but running inse开发者_如何学编程rt query on every refresh and values are duplicating in MySQL table.

Here is the code:

$isexist = mysql_query("select count(*) from wcddl_filehosts where downloadid = '".$download[id]."'");

if (mysql_num_rows($isexist) == 0) {
mysql_query("insert into wcddl_filehosts (downloadid, rs) values ('".$download[id]."','$totalRS')");
} else {
mysql_query("update wcddl_filehosts set rs = '$totalRS' where downloadid = '".$download[id]."'");
}

What's wrong with this?

---

Count will return a value, and you cannot count and then call mysql_num_rows. It is either one of the other.

You could do

$isExist = mysql_query("Select count(id) from ..."); 
$r = mysql_fetch_array($isExist);
if($r['COUNT(id)'] > 0){
//item exists
}else{
//item doesnt exist
}

If alternatively you can do the query as:

$isexist = mysql_query("select * from wcddl_filehosts where downloadid = '".$download[id]."'");
if(mysql_num_rows($isExists)>0){
//we have items
}else{
//we dont have items
}