首先说明几点:
1,excel格式的文件最大支持100万的数据,所以不考虑使用excel格式
2,laravel的toArray()方法有内存泄露,所以大量数据导出不能使用.
3,当然要使用chunk方法查询数据,然后写到文件中
关于toArray()方法内存泄露排查
chunk()方法的代码块如下(chunk中按理是不用unset的,会自动释放):
query−>chunk(1000,function(query->chunk(1000, function (query−>chunk(1000,function(data) use (&$firstWrite, $fp) {
Log::info(“开始:”.memory_get_usage());
$data = data−>toArray();Log::info("结束:".memorygetusage());unset(data->toArray();
Log::info("结束:".memory_get_usage());
unset(data−>toArray();Log::info("结束:".memorygetusage());unset(data);
Log::info(“usnet 结束:”.memory_get_usage());
});
在将一个“组块”的 Eloquent 模型转为数组的时候$data = $data->toArray();内存增加了很多.最后unset的时候又没有释放回初始值.实际上chunk中是不需要unset释放的.
解决
使用
DB::table(“xxx”)->->orderBy(xx)->chunk(xx);方式查询数据,查询结果在使用data=jsondecode(jsonencode(data = json_decode(json_encode(data=jsondecode(jsonencode(data), true);转换成数组,每次chunk执行进去,内存都是一样的,内部也不需要unset.
大数据导出最后做的方案
因为数据量大,所以我的做法是,小量数据导出就直接发送给用户.大数据导出,走队列任务,然后做一个报表管理,用户可以查看进度和完成后下载.
在浏览器中直接返回文件和后台写入文件
函数基本使用
fp=fopen("文件路径/文件名","a");//a表示追加模式fwrite(fp = fopen("文件路径/文件名", "a"); //a表示追加模式
fwrite(fp=fopen("文件路径/文件名","a");//a表示追加模式fwrite(fp, chr(0xEF).chr(0xBB).chr(0xBF)); // 添加 BOM,不然excel打开csv是乱码
在chunk的闭包中写数据: fputcsv($fp, array);fclose(array);
fclose(array);fclose(fp);
在队列中导出
fp=fopen(storagepath(′app/public/exports′)."/".fp = fopen(storage_path('app/public/exports')."/".fp=fopen(storagepath(′app/public/exports′)."/".report->name, “a”);
fwrite($fp, chr(0xEF).chr(0xBB).chr(0xBF)); // 添加 BOM
$firstWrite = true;
$query = expoter−>customQuery(expoter->customQuery(expoter−>customQuery(query);
query−>orderBy(query->orderBy(query−>orderBy(tableName.".id")->chunk(1000, function (KaTeX parse error: Expected 'EOF', got '&' at position 12: data) use (&̲firstWrite, $fp, $expoter) {
data=jsondecode(jsonencode(data = json_decode(json_encode(data=jsondecode(jsonencode(data), true);
$data = $expoter->customData($data);
//有一些列总是不导出,如icon,image,images
$data = ExportUtils::removeInvalids($data);
//写列名
if ($firstWrite) {
$columnNames = [];
//获取列名
foreach ($data[0] as $key => $value) {
$columnNames[] = admin_translate($key, "coupon");
}
fputcsv($fp, $columnNames);
$firstWrite = false;
}
foreach ($data as $item) {
fputcsv($fp, $item);
}
});
fclose($fp);
在浏览器中返回数据
response=newStreamedResponse(null,200,[′Content−Type′=>′text/csv′,′Content−Disposition′=>′attachment;filename="′.response = new StreamedResponse(null, 200, [
'Content-Type' => 'text/csv',
'Content-Disposition' => 'attachment; filename="'.response=newStreamedResponse(null,200,[′Content−Type′=>′text/csv′,′Content−Disposition′=>′attachment;filename="′.fileName.’"’,
]);
response−>setCallback(function()use(response->setCallback(function () use (response−>setCallback(function()use(query, $tableName) {
out=fopen(′php://output′,′w′);fwrite(out = fopen('php://output', 'w');
fwrite(out=fopen(′php://output′,′w′);fwrite(out, chr(0xEF).chr(0xBB).chr(0xBF)); // 添加 BOM
$firstWrite = true;
$query = $this->customQuery($query);
$query->orderBy($tableName.".id")->chunk(500, function ($data) use (&$firstWrite, $out) {
$data = json_decode(json_encode($data), true);
$data = $this->customData($data);
//有一些列总是不导出,如icon,image,images
$data = ExportUtils::removeInvalids($data);
//写列名
if ($firstWrite) {
$columnNames = [];
//获取列名
foreach ($data[0] as $key => $value) {
$columnNames[] = admin_translate($key, "coupon");
}
fputcsv($out, $columnNames);
$firstWrite = false;
}
foreach ($data as $item) {
fputcsv($out, $item);
}
});
fclose($out);
});
$response->send();