RE: [PHP] PHP Add +1 mysql updates by 2?

> -----Original Message----- > From: Tamara Temple [mailto:tamouse.lists@gmail.com] > Sent: Friday, November 26, 2010 7:54 PM > To: Richard West > Cc: PHP General Mailing List > Subject: Re: [PHP] PHP Add +1 mysql updates by 2? > > > On Nov 26, 2010, at 8:36 PM, Richard West wrote: > > > Hey guys, > > I've never run into this before. > > I have a field in mysql for page views. > > So I pull out value and do +1 to new value - after UPDATE SET it has > > incremented by 2? > > > > $val = $row['a_downloads'] ; > > > > $new_val = $val+1; > > > > mysql_query("UPDATE cbn_articles SET a_downloads='$new_val' WHERE > a_id > > = '".$_GET['id']."' "); > > > > Any ideas? What am I missing? > > RD > > a_downloads wouldn't happen to be an autoincrement value, would it? > IIRC, the auto_increment should only increment on an INSERT statement and the field is omitted. Besides, in MySQL, auto_increment must also be part of the primary key. From Richard's query, I'd say that his primary key field is most likely a_id. IMO, the best way to count something is to set the field to an int(eger) type. Then just run 'UPDATE table_name SET count_field = count_field +1 WHERE criteria_column = $criteria'. This is more safe as you many have simultaneous users downloading. This would ensure an accurate count, whereas your logic wouldn't. Regards, Tommy PS: Richard, you should validate and sanitize all inputs. Your query is prone to injection attack (deletion of rows or your entire DB deleted). Use either mysql_escape_string or, better yet, mysqli to prepare the statement and bind the parameters.