php - PHP根据查询结果构造多维数组

Question

试图将学期、班级、学生的 3 层数组组合在一起，形成候补名单清算页面。这是我用来创建数组的 foreach，但有些地方不对劲。生成的数组不适合循环并制作学期 > 课程 > 学生的 html 表。我的 foreach 看起来像这样

    foreach ($active_terms as $term) {
    $waitlists[ $term['term_id'] ] = $term;
        foreach ($active_courses as $course) {
            if ( ($course['term_id'] == $term['term_id']) && ($course['students_waitlisted'] > 0) ) {
            $waitlists[ $term['term_id'] ][ $course['course_id'] ] = $course;                   
                    foreach ($waitlisted_reservations as $reservation) {
                        if ( ($term['term_id'] == $reservation['term_id'])
                                && ($course['course_id'] == $reservation['course_id']) ) {
                            $waitlists[ $term['term_id'] ][ $course['course_id'] ][ $reservation['reservation_id'] ] = $reservation;
                        }   
                    }
            }
        }               
}

结果数组很接近，但看起来像这样：

Array
(
[1] => Array
    (
        [term_id] => 1
        [term_title] => Summer Session 1
        [term_begin_date] => June 25 2012
        [3] => Array
            (
                [term_id] => 1
                [course_id] => 3
                [course_title] => Biology 1
                [course_student_limit] => 8
                [students_reserved] => 6
                [students_registered] => 0
                [students_waitlisted] => 3
                [175] => Array
                    (
                        [term_id] => 1
                        [course_id] => 3
                        [reservation_id] => 175
                        [reservation_grade_level] => 12
                        [student_sis_id] => 289055
                    )
                [173] => Array
                    (
                        [term_id] => 1
                        [course_id] => 3
                        [reservation_id] => 173
                        [reservation_grade_level] => 08
                        [student_sis_id] => 111988
                    )
            )
    )
[2] => Array
    (
        [term_id] => 2
        [application_id] => 2
        [term_title] => Summer Session 2
        [term_begin_date] => July 23 2012
        [18] => Array
            ( ....

有人可以指出我如何正确地制作亲子巢吗？或者这个数组是否正确，我搞砸了如何使用嵌套的 foreach 来构建表格？

Answer 1

您必须再介绍一个级别。例如，替换：

$waitlists[ $term['term_id'] ][ $course['course_id'] ] = $course;

有了这个：

$waitlists[ $term['term_id'] ]['courses'][ $course['course_id'] ] = $course;

更新

为了让自己保持清醒，您还可以在 中使用引用foreach，例如：

foreach ($active_terms as $term) {
$waitlists[ $term['term_id'] ] = $term;
    foreach ($active_courses as $course) {
        if ( ($course['term_id'] == $term['term_id']) && ($course['students_waitlisted'] > 0) ) {
        $waitlists[ $term['term_id'] ][ $course['course_id'] ] = $course;  

也可以写成：

foreach ($active_terms as $term) {
    $waitlists[ $term['term_id'] ] = $term;
    $current_courses = &$waitlists[ $term['term_id'] ]['courses'];

    foreach ($active_courses as $course) {
        if ( ($course['term_id'] == $term['term_id']) && ($course['students_waitlisted'] > 0) ) {
        $current_courses[ $course['course_id'] ] = $course;  

缩短变量名称。您可能可以从那里解决其余的问题:)