我如何在 PHP 中划分两个语句

How I can divide two statement in PHP

<?php
     $q2 = "SELECT SUM(crd)
           FROM coe_courses
           INNER JOIN student_record ON coe_courses.course_number = 
            student_record.course_number WHERE student_record.id =".$_SESSION['user_id'] ;
     $result = mysqli_query($con , $q2 ) ;
     if($row = mysqli_fetch_array($result)){
         echo $row["SUM(crd)"];
     }
     $q2a = "SELECT SUM(points) FROM student_record where student_record.id =".$_SESSION['user_id'] ;
     $result = mysqli_query($con , $q2a ) ;
     if($row = mysqli_fetch_array($result)){
       echo $row["SUM(points)"];
     }
?>

我写了这段代码,但是我如何在这段代码的末尾对这些语句进行除法

echo $row["SUM(crd)"] /$row["SUM(points)"];

首先,您应该将这两个值存储在不同的变量中,因为根据您的代码,您将覆盖 $row 变量,因此您只会得到第二个结果。之后你可以简单地这样做。

if(!empty($b)) {
   $ans = (int) ($a/$b);
}