simple math

[tobimichigan]

Code Gurus Please help.

I am trying to make a calculation from 2 boxes namely $apaid & $adue to make a third $adebt like saying $adebt=$adue-$apaid

All three values would then go right into the db. But whenever I click the submit form the form the $adebt column remains blank while other values go straight in. Please can someone tell me what I'm doing wrong here?

<?php

//session_start();
include("cn.php");

$adue=$_GET['adue'];
$apaid=$_GET['apaid'];
//$adebt=$adue-$apaid;
//$username=$_GET['[$_SESSION[username]'];


$adno= mysql_real_escape_string($_POST['adno']);
$adue= mysql_real_escape_string($_POST['adue']);
$apaid = mysql_real_escape_string($_POST['apaid']);
$adebt=($adue-$apaid)== mysql_real_escape_string($_POST['adebt']);
$datereg = mysql_real_escape_string($_POST['datereg']);
$username= mysql_real_escape_string($_POST['username']);


$sql= "Insert into receipts(adno,adue,apaid,adebt,datereg,username) values('$adno','$adue','$apaid','$adebt',SYSDATE(),'$_SESSION[username]')";  
	                            
if (!mysql_query($sql))
{
  die('Error: ' . mysql_error()."  SQL: ".$sql);
  }
else
header ("Location:Receipt_Success.php");
?>

[Mchl]

Just like you did it in your other topic:

$adebt=$adue-$apaid;

 

are you having any problems with that?

 

[edit]

 

And this:

$adebt=($adue-$apaid)== mysql_real_escape_string($_POST['adebt']);

has no chance of doing anything useful.

[ignace]

$adebt=($adue-$apaid)== mysql_real_escape_string($_POST['adebt']);

 

After this $adebt==false; as $_POST['adebt'] != $adue-$apaid

 

So it's

 

$adebt = mysql_real_escape_string($_POST['adebt']);

$adebt = $adue - $apaid;

 

As you saw nothing that tells me you used varchar or something for your integer fields otherwise you would have got 0

 

However this makes no sense at all?!?

[tobimichigan]

$adebt=($adue-$apaid)== mysql_real_escape_string($_POST['adebt']);

 

After this $adebt==false; as $_POST['adebt'] != $adue-$apaid

 

So it's

 

$adebt = mysql_real_escape_string($_POST['adebt']);

$adebt = $adue - $apaid;

e

However this makes no sense at all?!?

I don't understand what you mean ignance. Mchl, the accurate value to be returned by the calculation is indicating 0 instead of the math value still what am I doing wrong?

[Mchl]

Mchl, the accurate value to be returned by the calculation is indicating 0 instead of the math value still what am I doing wrong?

 

THIS. This is wrong!

$adebt=($adue-$apaid)== mysql_real_escape_string($_POST['adebt']);

[ignace]

Mchl, the accurate value to be returned by the calculation is indicating 0 instead of the math value still what am I doing wrong?

 

THIS. This is wrong!

$adebt=($adue-$apaid)== mysql_real_escape_string($_POST['adebt']);

 

Which also explains the 0 as false in an integer context shows up as 0 and like Mchl said it's:

 

$adebt=($adue-$apaid);

 

It's that simple get rid of that .._string($_POST['adebt']);

[ignace]

I also want to give you some friendly advice: buy a book on software development and read the sections about variable types and conversions very carefully. A good start: http://www.php.net/manual/en/language.types.php

 

You should just like me be able to tell that after the instruction:

 

$adebt=($adue-$apaid)== mysql_real_escape_string($_POST['adebt']);

 

$adebt = false; and that in an integer context it translates to 0 unless $adue - $apaid indeed match adebt in which $adebt = true and 1 shows up in your db if you had used === then $adebt would have always been false (yes, you must be able to tell that in a blink of an eye)

[tobimichigan]

wait a minute ignace, you said something that seems to strike a cord, I am using a varchar..instead of integer in the column adebt could that be the problem? You sound confusing atimes ignace almost hiting the nail on the head.... could you please be more precise?

[Mchl]

I'll try be as precise as I can.

 

Instead of:

$adebt=($adue-$apaid)== mysql_real_escape_string($_POST['adebt']);

 

do:

$adebt=$adue-$apaid;