PHP - Display Calculation Problem For Each Row From Database

This code was given to me by mjdamato to help display a student and the course that student has take and within that the modules in the course and the sessions in course including module mark and grade and student's session marks and grades. I am very weak on php code as I have only done it once and that was following a php workbook 2 years ago. I am more of a database specialist. Below is the code given to me and you can also download the code from the attachment:

Code: [Select]
<?php

function outputModule($moduleID, $moduleName, $sessionData)    
  
  {        
  
  if(!count($sessionData)) { return false; }        
  
  $markTotal = 0;        
  $markGrade = 0;
  $weightSession = 0;
  $grade = "";
  $sessionsHTML = "";
  
  foreach($sessionData as $session)        {           
  
   $sessionsHTML .= "<p><strong>Session:</strong> {$session['SessionId']} <br><strong>Session Mark:</strong> {$session['Mark']}</strong> <br><strong>Session Weight Contribution</strong> {$session['SessionWeight']}%</p>\n";            
   $markTotal += round($session['Mark'] / 100 * $session['SessionWeight']); 
   $weightSession  += ($session['SessionWeight']);  
   $markGrade = round($markTotal /  $weightSession * 100);
   
if ($markGrade >= 70){
$grade = "A";}      

else if ($markGrade >= 60 && $markGrade <= 69){
$grade = "B";}

else if ($markGrade >= 50 && $markGrade <= 59){
$grade = "C";}

else if ($markGrade >= 40 && $markGrade <= 49){
$grade = "D";}

else if ($markGrade >= 30 && $markGrade <= 39){
$grade = "E";}

else if ($markGrade >= 0 && $markGrade <= 29){
$grade = "F";}
   
   }        
   
   $moduleHTML = "<p><br><strong>Module:</strong> {$moduleID} - {$moduleName} <br><strong>Module Mark:</strong> {$markTotal} <br><strong>Mark Percentage:</strong> {$markGrade} <br><strong>Grade:</strong> {$grade} </p>\n";       
   
    return $moduleHTML . $sessionsHTML;    }    
    
    $output = "";    
    
    $studentId = false;    
    $courseId  = false;    
    $moduleId  = false;    
    
    while ($row = mysql_fetch_array($result))    {               
     
     if($studentId != $row['StudentUsername'])        {            
     
     //Student has changed              
     $studentId = $row['StudentUsername'];                    
     
     $output .= "<p><strong>Student:</strong> {$row['StudentForename']} {$row['StudentSurname']} ({$row['StudentUsername']})\n";          
     
      }        
      
     if($courseId != $row['CourseId'])        {         
      
      //Course has changed           
       $courseId = $row['CourseId'];                    
       
       $output .= "<br><strong>Course:</strong> {$row['CourseId']} - {$row['CourseName']} <strong>Course Mark</strong> <strong>Grade</strong>  <br><strong>Year:</strong> {$row['Year']}</p>\n";           
       
        }      
        
 if($moduleId != $row['ModuleId'])        {            
 
 //Module has changed            
 if(isset($sessionsAry)) //Don't run function for first record           
 
  {              
  
    //Get output for last module and sessions                
    $output .= outputModule($moduleId, $moduleName, $sessionsAry);            }            
    
    //Reset sessions data array and Set values for new module           
    
     $sessionsAry = array();            
     $moduleId    = $row['ModuleId'];         
     $moduleName  = $row['ModuleName'];        }        
     
     //Add session data to array for current module      
     
     $sessionsAry[] = array('SessionId'=>$row['SessionId'], 'Mark'=>$row['Mark'], 'SessionWeight'=>$row['SessionWeight']);    
     
     }    //Get output for last module  
     
      $output .= outputModule($moduleId, $moduleName, $sessionsAry);   
      
       //Display the output    
       echo $output;

      }
  }
    ?>
Below the what this code outputs:


Student: Mayur Patel (u0867587)
Course: INFO101 - Bsc Information Communication Technology       Course Mark
Year: 3


Module: CHI2550 - Modern Database Applications        Module Mark: 41          Mark Percentage: 68            Grade: B

Session: AAB             Session Mark: 72               Session Weight Contribution 20%

Session: AAE             Session Mark: 67               Session Weight Contribution 40%


Module: CHI2513 - Systems Strategy            Module Mark: 31           Mark Percentage: 62            Grade: B

Session: AAD              Session Mark: 61             Session Weight Contribution 50%


If you look above it shows that there is nothing in the Course Mark: section, what Course Mark is suppose to do is total up all the module mark percentages and then divide it by the number of modules. So the calculation will be adding up all the Code: [Select]
$markGrade and dividing it by count Code: [Select]
$ModuleID. In examle above it will be 68 (mark percentage for 1st module) + 62 (mark percentage for 2nd  module) / 2 (number of modules in the course). So the Course Mark should equal 65. 

The problem is that all of the calculations are in the foreach loop but where the course details and where the course marks are going to be placed are in the while loop. So the problem is that if the total Course Mark (lets say we call in $totalCourse) is displayed in the while loop it will provide an undifined index as the calculation will be placed with the other calculations in the foreach loop which is outside the while loop, if I do the calculation with in the while loop, it will only choose the 1st module mark percentage and divdie it by the first module only, this is obviously incorrect as it sohuld try and do this for all modules hence why my calculations are in the foreach loop which does this.

So how will change the code so that the course details can go from the while loop and be placed in the foreach loop so then I can include the calculation in the foreach loop.

Thank You and hopefully you understand it, just read it very carefully to understand it, it is very simple what I want to achieve but I do not know how to do it.

[attachment deleted by admin]

I'm trying to simply display the contents of an entire database for the purpose of building an administrative super-user into the back-end to remove login credentials without having to resort to having to manually interact with Mariadb or PHPmyadmin. However, the code is only returning the last row that was entered into the database. I can't seem to figure out why it's not working as intended. The code is intended to simply display the entire contents of the database into an html table.

The code i'm using:

<?php 
$link = mysqli_connect("127.0.0.1", "database user", "password", "login");

if (!$link) {
    echo "Error: Unable to connect to MySQL." . PHP_EOL;
    echo "Debugging errno: " . mysqli_connect_errno() . PHP_EOL;
    echo "Debugging error: " . mysqli_connect_error() . PHP_EOL;
    exit;
            }

if ($result = mysqli_query($link, "SELECT * FROM accounts", MYSQLI_STORE_RESULT)) {

	while ($row = $result->fetch_assoc()) {
	$id = $row["id"];
	$username = $row["username"];
	$pass = $row["password"];
	$email = $row["email"];
	$su = $row["su"];
        }

   }
mysqli_close($link);
?>
<!DOCTYPE html>
<html>
	<head>

	</head>

	<body>
		<table>
		<tr> <th>id</th><th><th>user name</th><th>password</th><th>email</th><th>elevated privlege</th></tr>
                <tr>
		<td>   <?php echo $id; ?>    </td>
	        <td>   <?php echo $username; ?>      </td>
		<td>   <?php echo $pass; ?> </td>
                <td>   <?php echo $email; ?> </td>
                <td>   <?php echo $su; ?> </td>
                </tr>
                </table>
	</body>
</html>

 

Edited August 31, 2020 by bakertaylor28
correction of the code used.

As we know the total number of hits to database is proportional to the number of page views if page views * queries per page is more than the capacity of your database, then mysql queries may show  problem.  is there any way to calculate the database capacity ? I googled someone says 128Mb cache is there for mysql.

This is a bit of a puzzle. Look at the sum and result below:

Code: [Select]
$markTotal += ($session['Mark'] / 100 * $session['SessionWeight']);

Result on Browser with explanation to help you:

Module: CHI2550 - Modern Database Applications     35% (this is $markTotal)   ... This is where I want add the total mark for 100%

Session: AAB        100% (this is $session['Mark'])      10% (this is  $session['SessionWeight'])

Session: AAE       50% (this is $session['Mark'])     50%  (this is  $session['SessionWeight'])

All percentage marks above are just add ons.


As you can see the answer to the calculation above is right, the answer is 35 as it adds up the two session marks, divide by 100 and then times it by the total amount of the percentage.

But I want to include a total mark where except it is out of the total session percentage (60% for above example as one Session is 40% and the other is 20%), it is out of a 100% but I can not work as simple as that as in above example one session is worth more than other. The total mark out of 100% of the above example should be 65%, but how do I achieve this in my calculation. It is not as simple as dividing the $session['Mark'] because one session is worth more than the other. So the above example will have 2 marks: one mark out of total percentage of the Sessions which for the above example is 35% and second mark is out of the full 100% of the module which is 65%.

Thank you and any help is much appreciated

Hi,

I have a calculation issue in my php. Below is my code:

Code: [Select]
$output = "";
$studentId  = false;
$courseId  = false;
$moduleId  = false;
       
while ($row = mysql_fetch_array($result)){   

        $moduletotal += $row['Mark'];
       
        $modulemark = (int)($moduletotal);
         
//Above here is the calculation for add in the Marks of all the sessions

//Below is the code of the display of the query output


if($studentId != $row['StudentUsername'])  {       

$studentId = $row['StudentUsername'];       
$output .= "<p><strong>Student:</strong> {$row['StudentForename']} {$row['StudentSurname']} ({$row['StudentUsername']})";   

   }   
   
    if($courseId != $row['CourseId']) {   

$courseId = $row['CourseId'];       
$output .= "<br><strong>Course:</strong> {$row['CourseId']} - {$row['CourseName']} <br><strong>Year:</strong> {$row['Year']}</p>";   

}   

if($moduleId != $row['ModuleId'])  {       

   $moduleId = $row['ModuleId'];       
   $output .= "<p><br><strong>Module:</strong> {$row['ModuleId']} - {$row['ModuleName']} $modulemark</p>";   

  } 
   
   $output .= "<p><strong>Session:</strong> {$row['SessionId']} {$row['Mark']}</p>";
   
  }


Student: Mayur Patel (u0867587)
Course: INFO101 - Bsc Information Communication Technology 
Year: 3


Module: CHI2550 - Modern Database Applications 72 (72 is the answer to the calculation for the first module but this is incorrect at it should also add the 67 and thus become 139)

Session: AAB 72

Session: AAE 67

Module: CHI2513 - Systems Strategy 200 (200 is the answer to the calculation for this module but this is incorrect it should be only 61. But what it has done is that it has added the 72 and 67 from the first module and added it with the 61 in this module)

Session: AAD 61



SO WHAT MY QUESTION IS THAT HOW CAN I FIND THE TOTAL OF EACH MODULE MARK WHICH THE VARIABLE $modulemark = (int)($moduletotal); IS TRYING TO DO BY ADDING UP ALL THE SESSIONS MARKS WITHIN EACH MODULE.

I HAVE TRIED USING SUM(gr.Mark) in the query and using GROUP BY SessionId, ModuleId, StudentUsername, and CourseId but it ends up not being able to display any records. That is why I want to do the calculation using php rather than SQL.

BELOW IS THE QUERY IF YOU WANT TO SEE IT:

Code: [Select]
$query = "
          SELECT st.CourseId, c.CourseName, st.Year, st.StudentUsername, st.StudentForename, st.StudentSurname,
          s.ModuleId, m.ModuleName, m.Credits, s.SessionId, s.SessionWeight, gr.Mark, gr.Grade
          FROM Course c
          INNER JOIN Student st ON c.CourseId = st.CourseId
          JOIN Grade_Report gr ON st.StudentId = gr.StudentId
          JOIN Session s ON gr.SessionId = s.SessionId
          JOIN Module m ON s.ModuleId = m.ModuleId
          WHERE
          (st.StudentUsername = '".mysql_real_escape_string($studentid)."')
          ORDER BY c.CourseName, st.StudentUsername, m.ModuleName, s.SessionId
          ";