如何在数据库中插入2的商变量，然后将其作为百分比进行回显

Question

$score = 50
$total = 500
mysqli_query($conn,"UPDATE student_quiz SET `grade` = ".$score." out of ".$total."')

所以目前这将存储"；500〃中的50〃；在数据库中，但我希望它做的是存储$score和$total的商，所以它应该是"；0.1〃；而不是"；500〃中的50〃；。

当我显示它时，我如何将其作为百分比，使其变成"百分比"；10%"；当我呼应$等级而不是"；0.1〃；目前，这就是我获取和显示成绩的方式。

$query1 = mysqli_query($conn,"select * from student_class_quiz where class_quiz_id = '$id' and student_id = '$session_id'")or die(mysqli_error());
$row1 = mysqli_fetch_array($query1);
$grade = $row1['grade'];
<?php echo $grade; ?>

Answer 1

用$score/$total计算商。

$score = 50;
$total = 500;
$quotient = $score/$total;
$stmt = mysqli_prepare($conn,"UPDATE student_quiz SET `grade` = ?");
$stmt->bind_param("s", $quotient);
$stmt->execute();

要将其显示为百分比，请乘以100。

<?php
$query1 = mysqli_prepare($conn,"select * from student_class_quiz where class_quiz_id = ? and student_id = ?") or die(mysqli_error($conn));
$query1->bind_param("ss", $id, $session_id);
$query1->execute();
$result = $query1->get_result();
$row1 = $result->fetch_assoc($query1);
$grade = $row1['grade'];
echo "Grade percentage is " . round($grade*100) . "%";