Codeigniter: fetch and sum field values - php

Question

Please help with this...
I want to write a query to display sum of all marks of each student ( OR each record of a table - 1st CA + 2ND CA + EXAM SCORE = TOTAL).
I can display the marks successfully but can't fill in the 'Total'.
Please view the picture below.
View table
Please find my "mark table" and "subject table" structure below...
View table structure
Using the MVC architecture...
Here is my Model
function get_obtained_first_ca( $exam_id , $class_id , $subject_id , $student_id) {
$marks = $this->db->get_where('mark' , array(
'subject_id' => $subject_id,
'exam_id' => $exam_id,
'class_id' => $class_id,
'student_id' => $student_id))->result_array();
foreach ($marks as $row) {
echo $row['first_ca'];
}}
function get_obtained_second_ca( $exam_id , $class_id , $subject_id , $student_id) {
$marks2 = $this->db->get_where('mark' , array(
'subject_id' => $subject_id,
'exam_id' => $exam_id,
'class_id' => $class_id,
'student_id' => $student_id))->result_array();
foreach ($marks2 as $row) {
echo $row['second_ca'];
}}
function get_obtained_exam_score( $exam_id , $class_id , $subject_id , $student_id) {
$marks3 = $this->db->get_where('mark' , array(
'subject_id' => $subject_id,
'exam_id' => $exam_id,
'class_id' => $class_id,
'student_id' => $student_id))->result_array();
foreach ($marks3 as $row) {
echo $row['exam_score'];
}
}
Here is my autoload.php file content
$autoload['model'] = array('crud_model'); // The crud_model is my main model file.
Here is my controller
function __construct()
{
parent::__construct();
$this->load->database();
$this->load->library('session');
Here is my view
<table>
<tbody>
<thead>
<tr>
<td style="text-align: center;">Subject</td>
<td style="text-align: center;">1st CA</td>
<td style="text-align: center;">2nd CA</td>
...
<td style="text-align: center;">Total</td>
</tr>
</thead>
<?php
$total_marks = 0;
$total_grade_point = 0;
$subjects = $this->db->get_where('subject' , array(
'class_id' => $class_id , 'year' => $running_year
))->result_array();
foreach ($subjects as $row3):
?>
<tr>
<td style="text-align: center;"><?php echo $row3['name'];?></td>
<td style="text-align: center;">
<?php
$obtained_mark_query = $this->db->get_where('mark' , array(
'subject_id' => $row3['subject_id'],
'exam_id' => $exam_id,
'class_id' => $class_id,
'student_id' => $student_id ,
'year' => $this->db->get_where('settings' , array('type' => 'running_year'))->row()->description
));
if($obtained_mark_query->num_rows() > 0){
$marks = $obtained_mark_query->result_array();
foreach ($marks as $row4) {
echo $row4['first_ca'];
$total_marks += $row4['first_ca'];
}
}
?>
</td>
<td style="text-align: center;"><?php
$obtained_mark_query = $this->db->get_where('mark' , array(
'subject_id' => $row3['subject_id'],
'exam_id' => $exam_id,
'class_id' => $class_id,
'student_id' => $student_id ,
'year' => $this->db->get_where('settings' , array('type' => 'running_year'))->row()->description
));
if($obtained_mark_query->num_rows() > 0){
$marks = $obtained_mark_query->result_array();
foreach ($marks as $row4) {
echo $row4['second_ca'];
$total_marks += $row4['second_ca'];
}
}
?></td>
</td>
<td style="text-align: center;">
<?php
echo $total_mark; // Here is where I need to fetch my Total
?>
</tr>
<?php endforeach;?>
Your effort to help me fill the total column is highly appreciated. Thanks in advance!