I need help with these mathmatical operations in PHP...

[d00dle]

It doesn't work... anyone know why? I getno parse error, the math stuff doesn't work... ;_;

if ($_POST['buy']) {
$stocktotal=$st["total"];
$total=$shares * $stocktotal;
$sql="SELECT * FROM users WHERE username='$uname'";
$result=mysql_query($sql);
$myrow=mysql_fetch_array($result);
if ($myrow["aura"] < $total) {
echo "<tr><td colspan=3 class=sys align=center>You don't have enough $aura to purchase &quot;".stripslashes($shares)."&quot; share(s).</td></tr>";
} else {
if ($shares< 0) {
echo "<tr><td align=center colspan=3 class=sys>You cannot buy 0 shares.</td></tr>";
} else {
$auratotal = $myrow["aura"] - $total;
$stocktotal2 = $st["total"] + $shares;
$sharenumber = $st["shares"] + $shares;
$sql="UPDATE `users` SET `aura` = `aura` - '$total' WHERE `username` = '".$uname."'";
$result=mysql_query($sql);
$sql="UPDATE `stocks` SET `total` = '$stocktotal2'";
$result=mysql_query($sql);
$sql="UPDATE `stocks` SET `shares` = '$sharenumber'";
$result=mysql_query($sql);
$sql="UPDATE `users` SET `stockname` = ".$st['name']."";
$result=mysql_query($sql);
echo "<tr><td align=center colspan=3 class=sys>Your shares have been purchased.</td></tr>";
} } }
?>

[LordShryku]

Uh huh...and where's this $st array?

[Weedpacket]

And, um, what do you get?

(And where does $shares come from?)

[d00dle]

The $st gets the stuff from the db... $shares is the name for the number of shares that person is buying.

[d00dle]

oh and, whenever I try it it just gives me 'Your shares have been purchased' but it doesn't actually do any of that stuff.

[LordShryku]

Small rant....

Your coding needs work. Take a look at this. Not saying it's right, but it's to a standard. Indention. Seperate variables from strings every time. You use double quotes, and single quotes in your arrays. Pick one, and stick with it. Just take a look, try to code to some standard. Doesn't have to be mine, but some standard. And indention is in every standard.

Ok, enough rant, on to the code. I can't say exactly what is wrong here. But here is how you go about thoroughly debugging your code. Notice all the extra exho statements. This will show you where you're going wrong. Give it a shot.

<?
error_reporting(E_ALL);
if($_POST['buy']) { 
   $stocktotal=$st['total'];
   echo "Stocktotal: ".$stocktotal."<br>";

   $total= ($shares * $stocktotal);
   echo "Shares: ".$shares."<br>Total: ".$total."<br>";

   $sql="SELECT * FROM users WHERE username='".$uname."'";
   echo "SQL 1: ".$sql."<br>";

   $result=mysql_query($sql); 
   $myrow=mysql_fetch_array($result);
   echo "Aura: ".$myrow['aura']."<br>";
   echo "String Aura: ".$aura."<br>";

   if($myrow['aura'] < $total) { 
      echo "<tr>
              <td colspan=\"3\" class=\"sys\" align=\"center\">You don't have enough ".$aura." to purchase &quot;".stripslashes($shares)."&quot; share(s).</td>
            </tr>"; 
   }
   elseif($shares< 0) { 
         echo "<tr>
                 <td colspan=\"3\" class=\"sys\" align=\"center\">You cannot buy 0 shares.</td>
               </tr>"; 
   }
   else { 
      $auratotal = ($myrow['aura'] - $total);
      echo "Aura Total: ".$auratotal."<br>";

  $stocktotal2 = ($st['total'] + $shares);
  echo "Stock Total 2: ".$stocktotal2."<br>";

  $sharenumber = ($st['shares'] + $shares);
  echo "Share Number: ".$sharenumber."<br>";

  unset($sql);
  $sql="UPDATE users SET aura = ".$auratotal." WHERE username = '".$uname."'";
  echo "SQL 2: ".$sql;
  mysql_query($sql);

  unset($sql);
  $sql="UPDATE stocks SET total = '".$stocktotal2."'"; 
  echo "SQL 3: ".$sql;
  mysql_query($sql); 

  unset($sql);
  $sql="UPDATE stocks SET shares = '".$sharenumber."'"; 
  echo "SQL 4: ".$sql;
  mysql_query($sql); 

  unset($sql);
  $sql="UPDATE users SET stockname = '".$st['name']."'"; 
  echo "SQL 5: ".$sql;
  mysql_query($sql); 

  echo "<tr>
          <td colspan=\"3\" class=\"sys\" align=\"center\">Your shares have been purchased.</td>
        </tr>"; 
   }
}
?>

[Weedpacket]

One thing I have to ask about queries 3..5 is whether you really want to change those fields for every single record in the table, since that's what the code you've got will do.

I'm guessing that you really want to combine queries 2..5 into

$sql = "UPDATE
	users
SET
	aura = ".$auratotal.",
	total = '".$stocktotal2."',
	shares = '".$sharenumber."',
	stockname = '".$st['name']."'
WHERE
	username = '".$uname."'";

[LordShryku]

Looks like there's two table there Weed (users, stocks), but agreed, could be trimmed to two queries.

[d00dle]

If you havn't noticed already... I'm horrible at debugging... @_@

[Weedpacket]

Originally posted by LordShryku
Looks like there's two table there Weed (users, stocks), but agreed, could be trimmed to two queries.

Oh, true, sometimes users, sometimes stocks, then back to users again. Of course, that just means my question applies to both tables 🙂