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<p class="mb0 mt6">Closed <span title="2014-03-14 03:00:25Z" class="relativetime">6 years ago</span>.</p>
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I am currently working on a fun project, which involves Ajax, HTML, JavaScript, PHP and SQL.
I have debugged my project as far as I could, and I am 100% sure my AJAX, HTML and JavaScript are working fine and my variables are send to the server correctly.
I am trying to fetch data from the database, subtract a number (submitted in the form) from this data and update the database accordingly.
My database does update. However, it is not displaying the correct numbers. When submitting 1 in the form, it will ALWAYS return the same numbers in the database. (Which is odd, because I am subtracting it...). I am 100% sure the data from the form is passed to the server correctly, so I would like you all to check my server file, which should be the problem.
Edit: The database connection is made in db.php and is made correctly. This has been tested.
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I think you are mistaking the return value of mysql_query, look php's manual
mysql_query returns a resource which then may be passed to some other funcion to extract the value returned by the query you made. You should do something like this:
$res = mysql_query(...)
$row = mysql_fetch_assoc($res)
$dec = $res["column_name"] - $some_value
You should check the $_REQUEST[...] array values to eliminate sql injection vulnerabilities.
You really need to switch to prepared statements to fix your sql injection problems.
Apart from that, what's wrong with this specific code, is that mysql_query does not return a number, it returns a resource. You need to fetch a row to get the number.
as far as I know, mysql_query returns resource, not result itself. So you have to modify your code to something like this:
$res = mysql_query("your_query_here");
$row = mysql_fetch_row($res);
$totaalaantal = $row[0];