如何计算和显示学生的平均分数

Question

如何计算和显示学生的平均分数？

这是我的数据库表 https://i.stack.imgur.com/edMKs.jpg

Primary_model

$average = mysql_query("SELECT AVG(tot_score) AS avgscore FROM scores_primary");
while($row = mysql_fetch_array($average)){
echo $row['avgscore'];
}

控制器

$this->load->view('student/view',$data);

视图

<span><b>AVERAGE RESULT:</b><?php echo $row['avgscore']; ?></span>

不显示平均分数。我做错了什么？

Answer 1

如果你想要平均，你没有以正确的方式做到这一点，你可以更好地在控制器中创建一个函数，如下所示

function calculateaverage(){
$query = $this->db->select('AVG(totalscore) as average_score')->from('score')->get();
return $query->row()->average_score;
}

然后你可以调用它

function index(){
$data['avg'] = $this->calculateaverage();
$this->load->view('your-page', $data);
}

然后你可以在你的页面中回显它

<span><b>AVERAGE RESULT:</b><?php echo $avg; ?></span>

如果您想要特定学生的平均值，则可以将student_id传递给函数

function calculateaverage($student_id){
$query = $this->db->select('AVG(totalscore) as  average_score')->from('score')->where('student_id', $student_id)->get();
return $query->row()->average_score;
}

Answer 2

这就是对我有用的

学生控制器

//  $query = $this->db->query('SELECT AVG(tot_score) FROM scores_primary WHERE student_id = ?');
$sql = "SELECT AVG(tot_score) as average_score FROM scores_primary WHERE student_id = ?";
$query = $this->db->query($sql, array($student['id']));
$data['average_score'] = $query->result()[0]->average_score;

视图

<span><b>AVERAGE RESULT:<?php echo $average_score; ?></b></span>