problem with sql update

[saco721]

Hi!,

I am having problems with updating mysql database using isset. The code is:

<?php

if (isset($item_name)){

$query = "INSERT INTO downloads (user_name, item_name, total_downloads) VALUES('fred', 'doc1', '1')";	
}
else
{
$query = "UPDATE downloads SET total_downloads = total_downloads+1"; 
}

?>

I am trying to query the database to see if item_name is empty, if it is add the record, else just add 1 to downloads. The problem is that it never updates, it just adds a new record. Am I using isset incorrectly? How do I use isset with a database value? does the variable $item_name exist?

Any help would be greatfully appreciated.

[rulian]

Your update query has no WHERE clause, it would update all the rows in your table to add 1 to download

your condition if isset($item_name) determines which query gets executed.
if it's always adding then your condition is always true
If you are trying to determine if an item is already listed as a row in your database, you have to check with the DB first and then determine which sql to run

Something like

$Check=mysql_query("select * from `downloads` WHERE `item_name` = '".$item_name."' "); 

if (mysql_num_rows($Check) == 1) 
{
$query = "UPDATE `downloads` SET `total_downloads` = `total_downloads`+1 WHERE `item_name` = '".$item_name."' "; 
}
else 
{
$query = "INSERT INTO downloads (user_name, item_name, total_downloads) VALUES('fred', 'doc1', '1')"; 
}

[wilku]

look here http://dev.mysql.com/doc/refman/5.0/en/insert-on-duplicate.html
This way you'd have one query no matter if item_name exists or not. Of course item_name should be either unique or primary key.

[saco721]

Thanks for the code - problem solved

[bradgrafelman]

Don't forget to mark this thread resolved.