I have never used the INSERT or UPDATE commands in MySQL until now. So needless to say, I am writing this post because I am having a problem.

I am calling the following function only once on certain pages:

<?php
	if(isset($_GET['id'])){
		$sys->addPlay($_GET['id']);
	}
?>

and that function is defined as:

	function addPlay($gid){
		$quickcheck = "SELECT GamesPlayed FROM gamestoday WHERE Date = CURDATE() AND gId=$gid";
		if(@mysql_num_rows(mysql_query($quickcheck)) == 0){
			@mysql_query("INSERT INTO gamestoday VALUES (CURDATE(),0,$gid)");
		}
		$update2 = "UPDATE gamestoday SET GamesPlayed=GamesPlayed+1 WHERE Date = CURDATE() AND gId=$gid";

		@mysql_query($update2);
		
	}

I believe if this function is called only once that the Auto-Increment in $update2 should increase GamesPlayed only once for a given date and "gId", correct? I am seeing behavior where if I load a page once (and I'm sure I'm the only one loading it at that instant) GamesPlayed will increment anywhere between 1 and 4. So if I'm at GamesPlayed=5 and I load a given page the GamesPlayed for that page could be anywhere between 6 and 9. What gives? Am I doing something wrong in my code or overlooking something else?

Thanks!

That code is a disaster. You're running a SELECT, (sometimes an INSERT), and an UPDATE every time.

Try an INSERT.... UPDATE trigger.

This assumes that your primary key is set to gId + date ( PRIMARY KEY (gId, Date) )

If not, you'll have to adjust that.

PHP Code:

function addPlay($gid){
    $sql = "INSERT INTO gamestoday (Date, GamesPlayed, gId)
            VALUES (CURDATE(),1,$gid)
            ON DUPLICATE KEY
            UPDATE GamesPlayed=GamesPlayed+1";
    @mysql_query($sql);
} 


</span>

I agree it was a disaster and your code has both educated me and made my life simpler.

However, I still have the same problem... That both sets of code will increment GamesPlayed more than once on occasion. Could this be something with the browser requesting the page multiple times so that function gets called multiple times?

Thanks.

Sounds like a browser thing. Alternatively, it may be someone else looking at your website. You should have some PHP code using a Session variable or cookie to track updates and only run them conditionally, which will also prevent abuse.