如何计算和显示学生考试成绩

Question

我正在尝试使用PHP和MySQL数据库创建学生考试成绩系统。但是，我遇到了两个问题：

首先，输入CA1，CA2和考试的分数时，仅显示考试分数。似乎没有为CA1和CA2输入任何内容，它们也未显示在我的数据库中。

第二，如何自动计算CA1，CA2和考试的分数以获得总成绩？

这是我的代码

<div class="row">
  <div class="col-md-2"></div>
  <div class="col-md-8">
    <div class="panel panel-primary">
      <div class="panel-heading">
        <h3 class="panel-title">
          <?php echo get_phrase('Enter Subject Scores') ?>
        </h3>
      </div>
      <div class="panel-body">
        <?php echo form_open(site_url('admin/marks_update/'.$exam_id.'/'.$class_id.'/'.$section_id.'/'.$subject_id));?>
        <table class="table table-bordered">
          <thead>
            <tr>
              <th>#</th>
              <th>
                <?php echo get_phrase('id');?>
              </th>
              <th>
                <?php echo get_phrase('name');?>
              </th>
              <th>
                <?php echo get_phrase('CA1');?>
              </th>
              <th>
                <?php echo get_phrase('CA2');?>
              </th>
              <th>
                <?php echo get_phrase('Exam');?>
              </th>

            </tr>
          </thead>
          <tbody>
            <?php
                        $count = 1;
                        $marks_of_students = $this->db->get_where('mark' , array(
                                'class_id' => $class_id, 
                                'section_id' => $section_id ,
                                'year' => $running_year,
                                'subject_id' => $subject_id,
                                'exam_id' => $exam_id                           
                        ))->result_array();
                        foreach($marks_of_students as $row):
                    ?>
              <tr>
                <td>
                  <?php echo $count++;?>
                </td>

                <td>
                  <?php echo $this->db->get_where('student',array('student_id'=>$row['student_id']))->row()->student_code;?>
                </td>

                <td>
                  <?php echo $this->db->get_where('student' , array('student_id' => $row['student_id']))->row()->name;?>
                </td>
                <td>
                  <input type="text" class="form-control" name="ca1_<?php echo $row['mark_id'];?>" value="<?php echo $row['ca1'];?>">
                </td>
                <td>
                  <input type="text" class="form-control" name="ca2_<?php echo $row['mark_id'];?>" value="<?php echo $row['ca2'];?>">
                </td>
                <td>
                  <input type="text" class="form-control" name="marks_obtained_<?php echo $row['mark_id'];?>" value="<?php echo $row['mark_obtained'];?>">
                </td>

              </tr>
              <?php endforeach;?>
          </tbody>
        </table>

这就是正在显示的

<div class="row">
  <div class="col-md-12">
    <div class="panel panel-primary panel-shadow" data-collapsed="0">
      <div class="panel-heading">
        <div class="panel-title">
          <?php echo $row2['name'];?>
        </div>
      </div>
      <div class="panel-body">
        <div class="col-md-6">
          <table class="table table-bordered">
            <thead>
              <tr>
                <td style="text-align: center;">Subject</td>
                <td style="text-align: center;">CA1</td>
                <td style="text-align: center;">CA2</td>
                <td style="text-align: center;">Exam</td>
                <td style="text-align: center;">Highest Score</td>
                <td style="text-align: center;">Grade</td>

              </tr>
            </thead>
            <tbody>
              <?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' => $row2['exam_id'],
                                  'class_id' => $class_id,
                                  'student_id' => $student_id , 
                                  'year' => $running_year));
                      if ( $obtained_mark_query->num_rows() > 0) {
                          $marks = $obtained_mark_query->result_array();
                          foreach ($marks as $row4) {
                              echo $row4['CA1'];
                              $total_marks += $row4['mark_obtained'];
                          }
                      }
                  ?>
                </td>
                <td style="text-align: center;">
                  <?php
                      $obtained_mark_query = $this->db->get_where('mark' , array(
                                  'subject_id' => $row3['subject_id'],
                                  'exam_id' => $row2['exam_id'],
                                  'class_id' => $class_id,
                                  'student_id' => $student_id , 
                                  'year' => $running_year));
                      if ( $obtained_mark_query->num_rows() > 0) {
                          $marks = $obtained_mark_query->result_array();
                          foreach ($marks as $row4) {
                              echo $row4['CA2'];
                              $total_marks += $row4['mark_obtained'];
                          }
                      }
                  ?>
                </td>
                <td style="text-align: center;">
                  <?php
                      $obtained_mark_query = $this->db->get_where('mark' , array(
                                  'subject_id' => $row3['subject_id'],
                                  'exam_id' => $row2['exam_id'],
                                  'class_id' => $class_id,
                                  'student_id' => $student_id , 
                                  'year' => $running_year));
                      if ( $obtained_mark_query->num_rows() > 0) {
                          $marks = $obtained_mark_query->result_array();
                          foreach ($marks as $row4) {
                              echo $row4['mark_obtained'];
                              $total_marks += $row4['mark_obtained'];
                          }
                      }
                  ?>
                </td>
                <td style="text-align: center;">
                  <?php
                      $highest_mark = $this->crud_model->get_highest_marks( $row2['exam_id'] , $class_id , $row3['subject_id'] );
                      echo $highest_mark;
                  ?>
                </td>
                <td style="text-align: center;">
                  <?php
                      if($obtained_mark_query->num_rows() > 0) {
                          if ($row4['mark_obtained'] >= 0 || $row4['mark_obtained'] != '') {
                              $grade = $this->crud_model->get_grade($row4['mark_obtained']);
                              echo $grade['name'];
                              $total_grade_point += $grade['grade_point'];
                          }
                      }
                  ?>
                </td>
            </tr>
            <?php endforeach;?>
        </tbody>
    </table>

我怀疑这也是一个数据库问题，但我真的不知道从这里出发。 为此，我的数据库表名为“标记”，其中插入了以下内容
mark_id，student_id，subject_id，class_id，section_id，exam_id，ca1，ca2，mark_obtained，mark_total，评论，年份