在 laravel 中查看错误未定义变量
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/27747977/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
View in laravel error undefined variable
提问by kaern12
I am a newbie in laravel and php. I cannot show the results of query in laravel. I wrote this in my program.
我是 Laravel 和 php 的新手。我无法在 Laravel 中显示查询结果。我在我的程序中写了这个。
routes.php
路由文件
Route::get('books/see', function()
{
return View::make('books.absen');
});
Route::post('books/absen','BookController@absen');
BookController.php
图书控制器.php
public function absen()
{
$ruang = Input::get('ruangn');
$results = DB::select( DB::raw("SELECT id, name, isbn, ta, tb FROM book WHERE ta = '$ruang'"));
return Redirect::to('books/see');
}
absen.blade.php
absen.blade.php
<select name="ruangn" class="form-control" method="post" action="{{URL::to('books/absen')}}">
<?php
for( $i=1; $i<19; $i++ )
{
?>
<option>
<?php echo $i;
}
?>
</option>
</select>
<input type="submit" name="submit" value="Oke" class="btn btn-info">
<table class="table table-bordered table-striped">
<thead>
<th>No</th>
<th>Name</th>
<th>ISBN</th>
<th>TA</th>
<th>TB</th>
</thead>
<tbody>
@foreach ($results as $value)
<tr>
<td>{{$value->id}}</td>
<td>{{$value->name}}</td>
<td>{{$value->isbn}}</td>
<td>{{$value->ta}}</td>
<td>{{$value->tb}}</td>
</tr>
@endforeach
</tbody>
</table>
And error is Undefined variable: results (View: ...\absen.blade.php) I very tired with this. Help please
错误是未定义的变量：结果（视图：...\absen.blade.php）我对此感到非常厌烦。请帮忙
回答by lukasgeiter
Instead of redirecting, you should render the view in the absen()action. When doing the redirect the data you just selected from the db is all gone.
您应该在absen()操作中呈现视图，而不是重定向。进行重定向时，您刚刚从数据库中选择的数据全部消失了。
Try this:
尝试这个：
public function absen()
{
$ruang = Input::get('ruangn');
$results = DB::select( DB::raw("SELECT id, name, isbn, ta, tb FROM book WHERE ta = '$ruang'"));
return View::make('books/see')->with('results', $results);
}
Also you need to check if $resultsexists in your view, since you also want to display it when no results are available
您还需要检查$results视图中是否存在，因为您还希望在没有可用结果时显示它
@if(isset($results))
<table class="table table-bordered table-striped">
<thead>
<th>No</th>
<th>Name</th>
<th>ISBN</th>
<th>TA</th>
<th>TB</th>
</thead>
<tbody>
@foreach ($results as $value)
<tr>
<td>{{$value->id}}</td>
<td>{{$value->name}}</td>
<td>{{$value->isbn}}</td>
<td>{{$value->ta}}</td>
<td>{{$value->tb}}</td>
</tr>
@endforeach
</tbody>
</table>
@endif
Attention
注意力
André Daniel is very right with his comment. Your code is prone to SQL injection. You should really take a look at Laravels ORM Eloquentor the query builder. At the very minimum, use bindings for parameters:
安德烈·丹尼尔 (André Daniel) 的评论非常正确。您的代码容易受到 SQL 注入。你真的应该看看Laravels ORM口才或查询生成器。至少，使用参数绑定：
DB::select(DB::raw("SELECT id, name, isbn, ta, tb FROM book WHERE ta = ?"), array($ruang));
Here's an example with the query builder (Thanks @AndréDaniel)
这是查询构建器的示例（感谢@AndréDaniel）
DB::table("book")->where("ta", $ruang)->get()
回答by Corentin
You have to make your view with your variable.
Here is what you should do :
routes.php
你必须用你的变量来表达你的观点。
这是你应该做的：
routes.php
Route::get('books/see', function()
{
return View::make('books.absen');
});
Route::post('books/absen','BookController@absen');
BookController.php
图书控制器.php
public function absen()
{
$ruang = Input::get('ruangn');
$results = DB::select( DB::raw("SELECT id, name, isbn, ta, tb FROM book WHERE ta = '$ruang'"));
return View::make('books.absen')->with(array('results' => $results));
}
absen.blade.php
absen.blade.php
<select name="ruangn" class="form-control" method="post" action="{{URL::to('books/absen')}}">
<?php
for( $i=1; $i<19; $i++ )
{
?>
<option>
<?php echo $i;
}
?>
</option>
</select>
<input type="submit" name="submit" value="Oke" class="btn btn-info">
@if(isset($results))
<table class="table table-bordered table-striped">
<thead>
<th>No</th>
<th>Name</th>
<th>ISBN</th>
<th>TA</th>
<th>TB</th>
</thead>
<tbody>
@foreach ($results as $value)
<tr>
<td>{{$value->id}}</td>
<td>{{$value->name}}</td>
<td>{{$value->isbn}}</td>
<td>{{$value->ta}}</td>
<td>{{$value->tb}}</td>
</tr>
@endforeach
</tbody>
</table>
@endif
By the way, you should use Laravel form functions Forms & HTML
顺便说一句，你应该使用 Laravel 表单函数Forms & HTML
