Re: PHP Add +1 mysql updates by 2?

Hey Tommy, I get the same when seting it to a_downloads=a_downloads+1 It still increments by 2 I've never run into this before. RD On Nov 26, 2010, at 11:45 PM, Tommy Pham wrote: >> -----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. >