Question

这是为了向特定教师的学生展示。现在让您了解更多信息，请阅读以下声明：

我首先为所有课程创建了一个循环语句。然后，每个循环，我还插入另一个循环语句，让主题按程序显示特定教师和小组的每门课程的科目。然后我又提出了另一个循环语句来向学生展示每门课程。我已成功展示了学生，但问题是我不能算上所有学生。任何人？请帮我。顺便说一句，这是我的代码。

/* Get the Total Students */
$get_courses = $db_con->prepare("SELECT * FROM courses");
$get_courses->execute();

while ($course = $get_courses->fetch(PDO::FETCH_ASSOC)) {

    $get_subjs = $db_con->prepare("SELECT * FROM subjects WHERE course = :course AND f_id = :f_id GROUP BY COURSE");
    $get_subjs->bindparam(":course", $course["course_acronym"]);
    $get_subjs->bindparam(':f_id', $my_fac_id);
    $get_subjs->execute();

    while ($subjects = $get_subjs->fetch(PDO::FETCH_ASSOC)) {

        $get_stds = $db_con->prepare("SELECT * FROM students WHERE course = :course");
        $get_stds->bindparam(":course", $course['course_acronym']);

        $get_stds->execute();

        while ($stds = $get_stds->fetch(PDO::FETCH_ASSOC)) {

            echo $stds["firstname"] . ' ' . $stds["lastname"] . "<br/>";

        }

    }

}

非常感谢您的帮助。

Answer 1

在每个课程循环的学生中，您可以将当前学生分配到数组变量并通过计算得到学生总数：

/* Get the Total Students */
$get_courses = $db_con->prepare("SELECT * FROM courses");
$get_courses->execute();

while ($course = $get_courses->fetch(PDO::FETCH_ASSOC)) {

    $get_subjs = $db_con->prepare("SELECT * FROM subjects WHERE course = :course AND f_id = :f_id GROUP BY COURSE");
    $get_subjs->bindparam(":course", $course["course_acronym"]);
    $get_subjs->bindparam(':f_id', $my_fac_id);
    $get_subjs->execute();

    while ($subjects = $get_subjs->fetch(PDO::FETCH_ASSOC)) {

        $get_stds = $db_con->prepare("SELECT * FROM students WHERE course = :course");
        $get_stds->bindparam(":course", $course['course_acronym']);

        $get_stds->execute();

        while ($stds = $get_stds->fetch(PDO::FETCH_ASSOC)) {

            echo $stds["firstname"] . ' ' . $stds["lastname"] . "<br/>";
            $students[$stds["firstname"] . $stds["lastname"]] = '1';

        }

    }

}

$total_students = isset($students) ? count($students) : '0';

如何计算每个课程的Proffessor学生

1 个答案: