Read blob zip file directly without writing it to disk - powershell

Question

I'm using ODP.net with Powershell to get blob zipped file.
[void][System.Reflection.Assembly]::LoadFile("C:\DLL\Oracle.ManagedDataAccess.dll")
$OracleConnexion = New-Object Oracle.ManagedDataAccess.Client.OracleConnection('User Id=test;Password="test";Data Source=10.2.2.1/TEST')
$OracleConnexion.Open()
$Query=$OracleConnexion.CreateCommand()
$Query.CommandText="SELECT BLOB from MyTable Where ID=01"
$ExecuteQuery=$Query.ExecuteReader()
$Path = "C:\temp"
while ($ExecuteQuery.Read()){
$Localfile = New-Object IO.FileStream("$($Path)\$($ExecuteQuery["LOG_ID"]).zip",[IO.FileMode]::Create)
$Localfile.Write($ExecuteQuery["XML_TRACE"],0,$ExecuteQuery["XML_TRACE"].Length)
$Localfile.Close()
$Zip = [io.compression.zipfile]::OpenRead("$($Path)\$($Executequery["LOG_ID"]).zip")
$Stream = $Zip.Entries.Open()
$Reader = New-Object IO.StreamReader($stream)
$XML = $Reader.ReadToEnd()
$Reader.Close()
$Stream.Close()
$Zip.Dispose()
}
As you can see, first I'm writing file to disk with $Localfile.Write then with [io.compression.zipfile]::OpenRead i'm reading the content of my zipped file.
My code works, but I want to read my blob directly as zip file without writing it to disk, something like this :
while ($ExecuteQuery.Read()){
$Zip = [io.compression.zipfile]::OpenRead($ExecuteQuery["XML_TRACE"]).zip)
$Stream = $Zip.Entries.Open()
$Reader = New-Object IO.StreamReader($stream)
$XML = $Reader.ReadToEnd()
$XML
$Reader.Close()
$Stream.Close()
$Zip.Dispose()
}
EDIT : it works with ionic !
while ($ExecuteRequete.Read()){
$ZipStream = New-Object System.IO.Memorystream
$ZipStream.Write($ExecuteRequete["XML_TRACE"],0,$ExecuteRequete["XML_TRACE"].Length)
$ZipStream.Position = 0
$Zip = [Ionic.Zip.ZipFile]::Read($ZipStream)
$Stream = New-Object IO.MemoryStream
$Zip.Extract($Stream)
$stream.Position = 0
$Reader = New-Object IO.StreamReader($stream)
$XML = $Reader.ReadToEnd()
$Reader.Close()
$Stream.Close()
$ZipStream.Dispose()
$Zip.Dispose()
}

Answer 1

You can't do it with IO.Compression.Zipfile, see https://msdn.microsoft.com/en-us/library/system.io.compression.zipfile_methods(v=vs.110).aspx for all available methods
You could do it with Ionic zip. It can read zip from a stream:
clear
Add-Type -Path "E:\sw\NuGet\Packages\DotNetZip.1.9.7\lib\net20\Ionic.Zip.dll"
$zip = [Ionic.Zip.ZipFile]::Read($stream)
$file = $zip | where-object { $_.FileName -eq "XMLSchema1.xsd"}
$stream = new-object IO.MemoryStream
$file.Extract($stream)
$stream.Position = 0
$reader = New-Object IO.StreamReader($stream)
$text = $reader.ReadToEnd()
$text
$reader.Close()
$stream.Close()
$zip.Dispose()
Here's the doc: http://dotnetzip.herobo.com/DNZHelp/Index.html