我正在尝试使用Laravel作为csv文件导出数据库表。我希望用户能够选择Export as CSV按钮并将表格下载为csv文件。目前我已经得到了这个代码，但它无法正常工作：
我的按钮：
<a href="/all-tweets-csv" class="btn btn-primary">Export as CSV</a>
我的路线：
Route::get('/all-tweets-csv', function(){
$table = Tweet::all();
$filename = "tweets.csv";
$handle = fopen($filename, 'w+');
fputcsv($handle, array('tweet text', 'screen name', 'name', 'created at'));
foreach($table as $row) {
fputcsv($handle, array($row['tweet_text'], $row['screen_name'], $row['name'], $row['created_at']));
}
fclose($handle);
$headers = array(
'Content-Type' => 'text/csv',
);
return Response::download($handle, 'tweets.csv', $headers);
});
它返回给我这个错误：
The file "Resource id #154" does not exist
我已经收集到了，因为它正在尝试下载不存在的文件。有没有其他方法可以修改我的代码，以便下载为csv。
答案 0 :(得分：59)
我在这里偶然发现，试图看看Laravel是否默认内置了一些东西 - 这个问题的答案让我有点担心。我同意@andré-daniel说正确的方法是不先写一个文件，但是他的实现是手动将值组合在一起，如果任何值包含引号，空格等，则会失败。
这是一个更强大的解决方案，使用Laravel的Response::stream和php的fputcsv来正确格式化每一行（将转义引号，并引用必要的字符串。有关详细信息，请参阅http://php.net/manual/en/function.fputcsv.php）
<?php
public function download()
{
$headers = [
'Cache-Control' => 'must-revalidate, post-check=0, pre-check=0'
, 'Content-type' => 'text/csv'
, 'Content-Disposition' => 'attachment; filename=galleries.csv'
, 'Expires' => '0'
, 'Pragma' => 'public'
];
$list = User::all()->toArray();
# add headers for each column in the CSV download
array_unshift($list, array_keys($list[0]));
$callback = function() use ($list)
{
$FH = fopen('php://output', 'w');
foreach ($list as $row) {
fputcsv($FH, $row);
}
fclose($FH);
};
return Response::stream($callback, 200, $headers);
}
答案 1 :(得分：25)
除了这一行，几乎一切都很好：
return Response::download($handle, 'tweets.csv', $headers);
您应该将此行更改为：
return Response::download($filename, 'tweets.csv', $headers);
答案 2 :(得分：16)
编辑：请参阅this answer以获得更好的解决方案;我将在下面保留我的答案，但请注意，如果生成大文件，它会出现诸如无法转义值和使用不合理的内存量等问题。
您不必要地在磁盘上创建文件;如果两个人在同一时间请求该URL，则会导致磁盘IO并导致问题（框架的两个实例将写入同一个文件，并且会发生诸如服务损坏的文件或因异常而崩溃的错误）。< / p>
请改用：
Route::get('/all-tweets-csv', function() {
$tweets = Tweets::all();
// the csv file with the first row
$output = implode(",", array('tweet text', 'screen name', 'name', 'created at'));
foreach ($tweets as $row) {
// iterate over each tweet and add it to the csv
$output .= implode(",", array($row['tweet_text'], $row['screen_name'], $row['name'], $row['created_at'])); // append each row
}
// headers used to make the file "downloadable", we set them manually
// since we can't use Laravel's Response::download() function
$headers = array(
'Content-Type' => 'text/csv',
'Content-Disposition' => 'attachment; filename="tweets.csv"',
);
// our response, this will be equivalent to your download() but
// without using a local file
return Response::make(rtrim($output, "\n"), 200, $headers);
});
答案 3 :(得分：2)
考虑到the current highest ranked answer这是Laravel 5.7 CSV写入，请注意return的更改。
<?php
public function download()
{
$headers = [
'Cache-Control' => 'must-revalidate, post-check=0, pre-check=0'
, 'Content-type' => 'text/csv'
, 'Content-Disposition' => 'attachment; filename=galleries.csv'
, 'Expires' => '0'
, 'Pragma' => 'public'
];
$list = User::all()->toArray();
# add headers for each column in the CSV download
array_unshift($list, array_keys($list[0]));
$callback = function() use ($list) {
$FH = fopen('php://output', 'w');
foreach ($list as $row) {
fputcsv($FH, $row);
}
fclose($FH);
};
return (new StreamedResponse($callback, 200, $headers))->sendContent();
}
答案 4 :(得分：1)
除了这一行，一切看起来都很好：
return Response::download($handle, 'tweets.csv', $headers);
$handle未指向正确的文件路径。它应该是tweets.csv的完整路径，例如：
return Response::download($file, 'tweets.csv', $headers);
$file应该是$file = '/path/to/download/tweets.csv'
答案 5 :(得分：1)
以下是下载CSV的完整代码
$headers = array(
'Content-Type' => 'application/vnd.ms-excel; charset=utf-8',
'Cache-Control' => 'must-revalidate, post-check=0, pre-check=0',
'Content-Disposition' => 'attachment; filename=abc.csv',
'Expires' => '0',
'Pragma' => 'public',
);
$filename = "doenload.csv";
$handle = fopen($filename, 'w');
fputcsv($handle, [
"id",
"name"
]);
DB::table("tablename")->chunk(100, function ($data) use ($handle) {
foreach ($data as $row) {
// Add a new row with data
fputcsv($handle, [
$row->id,
$row->name
]);
}
});
fclose($handle);
return Response::download($filename, "download.csv", $headers);
答案 6 :(得分：0)
我跟随着这些示例，但没有一个为我的代码工作。我将附加为项目编写的代码作为示例。仅作为示例指南，这不涉及OP。我的数据是对象数组的形式
public function Export($data) {
$headers = array(
"Content-type" => "text/csv",
"Content-Disposition" => "attachment; filename=summary.csv",
"Pragma" => "no-cache",
"Cache-Control" => "must-revalidate, post-check=0, pre-check=0",
"Expires" => "0"
);
$columns = array('Period', 'RevenueArea', 'Subs');
$callback = function() use ($data, $columns)
{
$file = fopen('php://output', 'w');
fputcsv($file, $columns);
foreach($data as $items) {
fputcsv($file, array($items->PERIOD, $items->REVENUE_AREA, $items->SUBS));
}
fclose($file);
};
return Response::stream($callback, 200, $headers)->send();
}
如果您在我的return语句中注意到，我包括-> send（），它会生成csv文件并初始化下载。哪里-> sendContent（）;只是将日期转储到屏幕上。如果您偶然遇到与我没有下载文件相同的问题，请确保签出官方文档。
https://api.symfony.com/2.3/Symfony/Component/HttpFoundation/StreamedResponse.html
答案 7 :(得分：0)
尝试一下
public function exportCsv(Request $request)
{
$fileName = 'tasks.csv';
$tasks = Task::all();
$headers = array(
"Content-type" => "text/csv",
"Content-Disposition" => "attachment; filename=$fileName",
"Pragma" => "no-cache",
"Cache-Control" => "must-revalidate, post-check=0, pre-check=0",
"Expires" => "0"
);
$columns = array('Title', 'Assign', 'Description', 'Start Date', 'Due Date');
$callback = function() use($tasks, $columns) {
$file = fopen('php://output', 'w');
fputcsv($file, $columns);
foreach ($tasks as $task) {
$row['Title'] = $task->title;
$row['Assign'] = $task->assign->name;
$row['Description'] = $task->description;
$row['Start Date'] = $task->start_at;
$row['Due Date'] = $task->end_at;
fputcsv($file, array($row['Title'], $row['Assign'], $row['Description'], $row['Start Date'], $row['Due Date']));
}
fclose($file);
};
return response()->stream($callback, 200, $headers);
}
答案 8 :(得分：-1)
试试这个
$file_name = "abc";
$postStudent = Input::all();
$ck = DB::table('loan_tags')->select('LAN')->where('liabilitiesId', $postStudent['id'])->get();
$i = 0;
foreach ($ck as $row) {
$apps[$i]['LAN'] = $row->LAN;
$apps[$i]['Account_number'] = $postStudent['account_number'];
$apps[$i]['Bank_Name'] = $postStudent['bank_name'];
$i++;
}
ob_end_clean();
ob_start();
Excel::create($file_name, function($excel) use($apps){
$excel->sheet('Sheetname', function($sheet) use($apps){
$sheet->row(1, array(
'LAN', 'Account number' , 'Bank Name'
));
$k = 2;
foreach ($apps as $deta) {
$sheet->row($k, array($deta['LAN'], $deta['Account_number'], $deta['Bank_Name']
));
$k++;
}
});
})->download('xlsx');