如何解决使用 ZipArchive、CsvHelper 和 Azure Blob 将流内压缩到 csv 给我留下一个空的存档 C#
我正在尝试将转换为 csv 的 sql 查询的压缩结果上传到 blob。
请参阅下面的代码:
//this doesn't work
using (var sqlCommand = _dataPointService.OpensqlConnectionForCsvQuery(device,start,end))
using (var sqlDataReader = sqlCommand.ExecuteReader(CommandBehavior.CloseConnection))
using (var blobWriteStream = appendBlobClient.OpenWrite(true))
using (var zipArchive = new ZipArchive(blobWriteStream,ZipArchiveMode.Create))
using (var streamWriter = new StreamWriter(zipArchive.CreateEntry(fileName + ".csv").open()))
using (var csvWriter = new CsvWriter(streamWriter,new CsvConfiguration(CultureInfo.InvariantCulture)))
{
var generator = new StreamCsvGenerator(device,end,showTemperatureInFahrenheit);
generator.FeedHeader(csvWriter);
{
while (sqlDataReader.Read())
{
generator.FeedRow(csvWriter,sqlDataReader);
}
}
streamWriter.Flush();
}
但是,如果我不费心压缩,一切都会好起来的:
//this works
using (var sqlCommand = _dataPointService.OpensqlConnectionForCsvQuery(device,end))
using (var sqlDataReader = sqlCommand.ExecuteReader(CommandBehavior.CloseConnection))
using (var blobWriteStream = appendBlobClient.OpenWrite(true))
using (var streamWriter = new StreamWriter(blobWriteStream))
using (var csvWriter = new CsvWriter(streamWriter,new CsvConfiguration(CultureInfo.InvariantCulture)))
{
var generator = new StreamCsvGenerator(device,sqlDataReader);
}
}
streamWriter.Flush();
}
我是否错误地使用了 ZipArchive / ZipEntry 流?我该如何解决?
解决方法
我相信您需要告诉 ZipArchive 保持 Stream
打开,以便您可以使用 CsvHelper
using (var zipArchive = new ZipArchive(blobWriteStream,ZipArchiveMode.Create,true))
如果这不起作用,您可以先写入 MemoryStream
,然后使用您的 appendBlobClient
上传。第一部分有效,我能够写入我计算机上的本地文件。我无法测试 appendBlobClient
部分,因为我没有使用 Azure 帐户进行设置。
using (var memoryStream = new MemoryStream())
{
using (var sqlCommand = _dataPointService.OpenSqlConnectionForCsvQuery(device,start,end))
using (var sqlDataReader = sqlCommand.ExecuteReader(CommandBehavior.CloseConnection))
using (var zipArchive = new ZipArchive(memoryStream,true))
using (var streamWriter = new StreamWriter(zipArchive.CreateEntry(fileName + ".csv").Open()))
using (var csvWriter = new CsvWriter(streamWriter,new CsvConfiguration(CultureInfo.InvariantCulture)))
{
var generator = new StreamCsvGenerator(device,end,showTemperatureInFahrenheit);
generator.FeedHeader(csvWriter);
{
while (sqlDataReader.Read())
{
generator.FeedRow(csvWriter,sqlDataReader);
}
}
streamWriter.Flush();
}
using (var blobWriteStream = appendBlobClient.OpenWrite(true))
{
memoryStream.Seek(0,SeekOrigin.Begin);
blobWriteStream.AppendBlock(memoryStream,memoryStream.Length);
}
}
,
解决方法是将我的 Azure.Storage.Blobs 包更新到最新版本。
我使用的是 12.6.0 版。更新到 12.8.3 后,一切正常。
以下是我的电话如何查找将来遇到此问题的任何人:
var appendBlobClient = BlobStorage.CreateAppendBlobClient(blobName);
using (var sqlCommand = _dataPointService.OpenSqlConnectionForCsvQuery(device,end))
using (var sqlDataReader = sqlCommand.ExecuteReader(CommandBehavior.CloseConnection))
using (var blobWriteStream = appendBlobClient.OpenWrite(true))
using (var zipArchive = new ZipArchive(blobWriteStream,ZipArchiveMode.Create))
using (var zipEntryStream = zipArchive.CreateEntry(fileName + ".csv").Open())
using (var streamWriter = new StreamWriter(zipEntryStream))
using (var csvWriter = new CsvWriter(streamWriter,new CsvConfiguration(CultureInfo.CurrentCulture)))
{
// this class is a csvWriter helper
var generator = new StreamCsvGenerator(device,showTemperatureInFahrenheit);
generator.FeedHeader(csvWriter); // this writes some comments at the top of the csv file
while (sqlDataReader.Read())
{
generator.FeedRow(csvWriter,sqlDataReader); // this writes records
}
}
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