在 Laravel 视图中使用 foreach 变量
Using a foreach variable in a Laravel view
我的 MySQL table 看起来像这样(相关部分):
student_id (int) | engmins(int) | totalmins(int) | created_at (datetime)
1 | 50 | 100 | 2017-12-15 00:00:00
1 | 20 | 45 | 2017-12-15 00:00:00
我有以下代码:
$students = StudentDetails::with('student','studentschool','classactivity')
->where('class', 1)
->orderBy('studentgrade', 'DESC')
->get();
$calculatePercentage = array();
foreach ($students as $s)
{
$fetchEngClassPercents= DB::table('ClassActivity')
->select(DB::raw('round((sum(engmins) * 60) / (sum(totalmins) * 60) * 100) as percents'))
->where('created_at', '>=', Carbon::now()->subDays(30))
->where('student_id', '=', $s->student->id)->get();
foreach($fetchEngClassPercents as $f)
{
$calculatePercentage = $f->percents;
var_dump($calculatePercentage); //Debug purposes
}
}
var_dump($calculatePercentage); //Debug purposes
$params = [
'engClassPercentage' => $calculatePercentage,
'studentInfo' => $students,
];
return view('user.classes.engclass.index', $params);
- var_dump 在循环内部执行 string(2) "43" NULL
- var_dump 在循环外执行 NULL
这是它在视图中的样子:
<td>
@foreach($engClassPercentage as $p)
{{ $p->percents }}
@endforeach
</td>
这在视图中不起作用,它什么也没显示。
出于某种原因,$calculatePercentage 在循环外保持为空(在先前尝试转储 var 时)。当它在 foreach 循环中时,它会执行查询。
奇怪的是,我在循环外声明了数组($calculatePercentage),并在 foreach 循环中为它分配了变量。
老实说,我现在很迷茫,如果能得到帮助,我会很高兴。
$calculatePercentage 在每个循环中被覆盖,将其更改为数组键
$calculatePercentage[] = $f->percents;
然后在你的 foreach 中调用 $params 数组
@foreach($params['engClassPercentage'] as $p)
您没有存储在 foreach 循环中计算的值:
因此,这些值不会按照您的要求持续存在。
更新代码:
foreach ($students as $s)
{
$fetchEngClassPercents= DB::table('ClassActivity')
->select(DB::raw('round((sum(engmins) * 60) / (sum(totalmins) * 60) * 100) as percents'))
->where('created_at', '>=', Carbon::now()->subDays(30))
->where('student_id', '=', $s->student->id)->get();
foreach($fetchEngClassPercents as $f)
{
$calculatePercentage[] = $f->percents; // <-- This line is edited.
}
}
更改 $calculate Percentage = $of-percents;喜欢下面。
然后在 foreach 部分将 $p->percents 更改为 $p.
$calculatePercentage[] = $f->percents;
@foreach($engClassPercentage as $p)
{{$p}}
@endforeach
我的 MySQL table 看起来像这样(相关部分):
student_id (int) | engmins(int) | totalmins(int) | created_at (datetime)
1 | 50 | 100 | 2017-12-15 00:00:00
1 | 20 | 45 | 2017-12-15 00:00:00
我有以下代码:
$students = StudentDetails::with('student','studentschool','classactivity')
->where('class', 1)
->orderBy('studentgrade', 'DESC')
->get();
$calculatePercentage = array();
foreach ($students as $s)
{
$fetchEngClassPercents= DB::table('ClassActivity')
->select(DB::raw('round((sum(engmins) * 60) / (sum(totalmins) * 60) * 100) as percents'))
->where('created_at', '>=', Carbon::now()->subDays(30))
->where('student_id', '=', $s->student->id)->get();
foreach($fetchEngClassPercents as $f)
{
$calculatePercentage = $f->percents;
var_dump($calculatePercentage); //Debug purposes
}
}
var_dump($calculatePercentage); //Debug purposes
$params = [
'engClassPercentage' => $calculatePercentage,
'studentInfo' => $students,
];
return view('user.classes.engclass.index', $params);
- var_dump 在循环内部执行 string(2) "43" NULL
- var_dump 在循环外执行 NULL
这是它在视图中的样子:
<td>
@foreach($engClassPercentage as $p)
{{ $p->percents }}
@endforeach
</td>
这在视图中不起作用,它什么也没显示。
出于某种原因,$calculatePercentage 在循环外保持为空(在先前尝试转储 var 时)。当它在 foreach 循环中时,它会执行查询。
奇怪的是,我在循环外声明了数组($calculatePercentage),并在 foreach 循环中为它分配了变量。
老实说,我现在很迷茫,如果能得到帮助,我会很高兴。
$calculatePercentage 在每个循环中被覆盖,将其更改为数组键
$calculatePercentage[] = $f->percents;
然后在你的 foreach 中调用 $params 数组
@foreach($params['engClassPercentage'] as $p)
您没有存储在 foreach 循环中计算的值:
因此,这些值不会按照您的要求持续存在。
更新代码:
foreach ($students as $s)
{
$fetchEngClassPercents= DB::table('ClassActivity')
->select(DB::raw('round((sum(engmins) * 60) / (sum(totalmins) * 60) * 100) as percents'))
->where('created_at', '>=', Carbon::now()->subDays(30))
->where('student_id', '=', $s->student->id)->get();
foreach($fetchEngClassPercents as $f)
{
$calculatePercentage[] = $f->percents; // <-- This line is edited.
}
}
更改 $calculate Percentage = $of-percents;喜欢下面。 然后在 foreach 部分将 $p->percents 更改为 $p.
$calculatePercentage[] = $f->percents;
@foreach($engClassPercentage as $p)
{{$p}}
@endforeach