运行 eloquent 循环并根据另一个 eloquent 查询的结果在 blade 中显示列表

Question

我有一个获取学生列表的查询，我正在使用 foreach 循环迭代并获取每个学生的 student_id。

在 foreach 循环内，我有另一个计算学生分数的查询。在计算学生分数时，我需要来自第一个查询的 student_id

逻辑

$students = DB::table('grades_students')
  ->join('users', 'grades_students.student_id', '=', 'users.id')
  ->join('grades', 'grades_students.grade_id', '=', 'grades.id')
  ->where('grades.stream_id', $request->stream_name)
  ->get()->pluck('student_id');


  foreach ($students as $student ) {

    $student_average=DB::select(DB::raw("select student_id,  round((SUM(t.mark))/'5') average_mark from (
        select marks.student_id,  ROUND(AVG(mark)) as mark  from marks
            INNER JOIN teaching_loads ON teaching_loads.id=marks.teaching_load_id
            INNER JOIN subjects ON subjects.id=teaching_loads.subject_id
        where marks.student_id = '$student' AND marks.assessement_id=1  
        GROUP BY subject_id
      )t "));

}
return view('analytics.view-test', compact('student_average'));

现在的问题是 blade 中只出现了一个学生，但我需要显示学生查询中所有学生的列表。

Answer 1

您正在覆盖 $student_average 每个循环，因此只有最后一个循环的内容存储在 $student_average 中。您需要改用数组。

$student_averages = [];
foreach ($students as $student) {
    $student_averages[] = DB::select(...your query);
}
return view('analytics.view-test', compact('student_averages'));

然后您将获得所有可用的学生平均成绩，并可以在您的视图中循环浏览它们。

Answer 2

你应该这样做

// Create an array to store the value
$student_average = [];

foreach ($students as $student) {
    // Push result to array
    $student_average[] = DB::select(DB::raw("select student_id,  round((SUM(t.mark))/'5') average_mark from (
    select marks.student_id,  ROUND(AVG(mark)) as mark  from marks
        INNER JOIN teaching_loads ON teaching_loads.id=marks.teaching_load_id
        INNER JOIN subjects ON subjects.id=teaching_loads.subject_id
    where marks.student_id = '$student' AND marks.assessement_id=1  
    GROUP BY subject_id
  )t "));
}

运行 eloquent 循环并根据另一个 eloquent 查询的结果在 blade 中显示列表

Running eloquent in loop and display list in blade based on result from another eloquent query

php

mysql

laravel

eloquent

laravel-blade