Powershell using System.Data.SqlDBType varbinary - sql-server

Question

I'm trying to import a ZIP-File from a SQL-Server. The column in der SQL-table is defined as varbinary(max). I'm using a SQL-stored procedure with an output parameter giving me this zip-file.
I defined (see code) an cmd.parameter (system.data.sqldbtype::varbinary,-1) , "-1" should be the "max"-length, but I get no records back ($rd.HasRecords is null..).
Thanks for your help.
Function Get-SQLData
{
$conn = New-Object System.Data.SqlClient.SqlConnection
$conn.ConnectionString = "Server=XXXX\YYYY;Database=SQL_XXX;Integrated Security=no;User=SQLServer_XX;Password=xxYYYY"
$conn.Open() | out-null
$cmd = new-Object System.Data.SqlClient.SqlCommand #("deployment.getZIPFile", $conn)
#Proz
$cmd.Connection = $conn
$cmd.CommandType = [System.Data.CommandType]::StoredProcedure
$cmd.CommandText = "deployment.getZIPFile"
#### Proz-Parameter
$cmd.Parameters.Add("#file_typ",[system.data.SqlDbType]::VarChar,5) | out-Null
$cmd.Parameters['#file_typ'].Direction = [system.data.ParameterDirection]::Input
$cmd.Parameters['#file_typ'].value = 'PS'
#
$cmd.Parameters.Add("#domain",[system.data.SqlDbType]::VarChar,5) | out-Null
$cmd.Parameters['#domain'].Direction = [system.data.ParameterDirection]::Input
$cmd.Parameters['#domain'].value = ($env:USERDNSDOMAIN).Split('.')[0] # domain
#
$cmd.Parameters.Add("#serverName",[system.data.SqlDbType]::VarChar,50) | out-Null
$cmd.Parameters['#serverName'].Direction = [system.data.ParameterDirection]::Input
$cmd.Parameters['#serverName'].value = $env:COMPUTERNAME #local server
#
$cmd.Parameters.Add("#scriptVersion",[system.data.SqlDbType]::decimal) | out-Null
$cmd.Parameters['#scriptVersion'].Direction = [system.data.ParameterDirection]::Input
$cmd.Parameters['#ScriptVersion'].Precision=18
$cmd.Parameters['#ScriptVersion'].Scale=2
$cmd.Parameters['#scriptVersion'].value = $MyVersion
#
$cmd.Parameters.Add("#operatingSystem",[system.data.SqlDbType]::VarChar, 100) | out-Null
$cmd.Parameters['#operatingSystem'].Direction = [system.data.ParameterDirection]::Input
$cmd.Parameters['#operatingSystem'].value = (gwmi -Class win32_operatingsystem).caption
#
$cmd.Parameters.Add("#serverTyp",[system.data.SqlDbType]::VarChar, 50) | out-Null
$cmd.Parameters['#serverTyp'].Direction = [system.data.ParameterDirection]::Input
$cmd.Parameters['#serverTyp'].value = $serverTyp
#
$cmd.Parameters.Add("#serverSubTyp",[system.data.SqlDbType]::VarChar, 50) | out-Null
$cmd.Parameters['#serverSubTyp'].Direction = [system.data.ParameterDirection]::Input
$cmd.Parameters['#serverSubTyp'].value = $serverSubTyp
#
$cmd.Parameters.Add("#aktScriptVersion",[system.data.SqlDbType]::decimal) | out-Null
$cmd.Parameters['#aktScriptVersion'].Direction = [system.data.ParameterDirection]::Output
$cmd.Parameters['#aktScriptVersion'].Precision=18
$cmd.Parameters['#aktScriptVersion'].Scale=2
#
$cmd.Parameters.Add("#ZIPFile",[system.data.SqlDbType]::varbinary,-1) | out-Null
$cmd.Parameters['#ZIPFile'].Direction = [system.data.ParameterDirection]::Output
#### Proz-Parameter Ende
#$cmd.ExecuteNonQuery() #| out-null ## org
$rd = $cmd.ExecuteReader() # gibt es Records?
#$rd = $cmd.ExecuteNonQuery()
if ($rd.HasRows) # gibt es Records?
{
$bufferSize = 8192
# Stream Lesen..
# Create a byte array for the stream.
$out = [array]::CreateInstance('Byte', $bufferSize)
# Looping through records
While ($rd.Read())
{
$fileLocation = "C:\PerfLogs\XXXX\ZIPImport.7z"
#Write-Output ("Exporting: {0}" -f $rd.GetInt32(0));
# New BinaryWriter
$fs = New-Object System.IO.FileStream $fileLocation,'Create','Write';
$bw = New-Object System.IO.BinaryWriter $fs;
$start = 0;
# Read first byte stream
$received = $rd.GetBytes(0, $start, $out, 0, $bufferSize - 1); ## 1
While ($received -gt 0)
{
$bw.Write($out, 0, $received);
$bw.Flush();
$start += $received;
# Read next byte stream
$received = $rd.GetBytes(0, $start, $out, 0, $bufferSize - 1); ## 1
}
$bw.Close();
$fs.Close();
}
# Closing & Disposing all objects
$fs.Dispose()
$rd.Close()
$cmd.Dispose()
$conn.Close()
Write-Output ("ZIP-Import Finished")
# 7z Sektion
$unzip = 'C:\PerfLogs\xxxx\Modul'
& ${env:ProgramFiles}\7-Zip\7z.exe x $fileLocation "-o$($unzip)" -y
Write-Output ("UNZIP Finished")
}
$conn.Close()
$conn.Dispose()
}
}

Answer 1

As mentioned in the comments that solved your problem, the parameters in your question are correct. The issue is with the code that executes the procedure and processes the result.
There is no need to use a SqlDataReader here because the proc returns the value in an output parameter instead of in a result set column. Also, since the entire byte array is returned, it is much easier to write the value directly to the file rather than in a read/write loop.
Below is one way to write the output parameter byte array to a file.
# execute the proc, returning the #ZIPFile output parameter
$cmd.ExecuteNonQuery() | out-null
if($cmd.Parameters["#ZIPFile"].Value -eq [System.DBNull]::Value) {
Write-Output "Zipfile not found in database"
}
else {
# write the byte arrary output value to a file
$fileLocation = "C:\PerfLogs\XXXX\ZIPImport.7z"
Write-Output "Exporting $($cmd.Parameters["#ZIPFile"].Value.Length) bytes to $fileLocation"
[System.IO.File]::WriteAllBytes($fileLocation, $cmd.Parameters["#ZIPFile"].Value)
}