Powershell: Text file update increase big file size - sql-server

Question

I wirte a XML file using SQL Server query result and I need to input a first line to ensure necessary head of file to integration of customer system.
I have sucess to create and update it, but the file is very large, for example from 2.4 MB to 120 MB.
Its caused by many blank lines the powershell insert when file is created.
See the script below.
function ProcToXmlFile {
param
(
[string]$outputType,
[string]$filename
)
$SqlConnection = New-Object System.Data.SqlClient.SqlConnection
$SqlConnection.ConnectionString = "Server=localhost;Database=customerdatabase;Integrated Security=True"
$SqlCmd = New-Object System.Data.SqlClient.SqlCommand
$Query = "select * from table where condition=1"
FOR
XML PATH('root'),
TYPE
)
FOR XML PATH(''),
ROOT('root')"
$SqlCmd.CommandText = $Query
$SqlCmd.Connection = $SqlConnection
$SqlAdapter = New-Object System.Data.SqlClient.SqlDataAdapter
$SqlAdapter.SelectCommand = $SqlCmd
$DataSet = New-Object System.Data.DataSet
$SqlAdapter.Fill($DataSet)
$SqlConnection.Close()
#$DataSet.Tables[0] | Format-Wide -AutoSize -Force
#$DataSet = -replace "\s", ""
$DataSet.Tables[0] | Format-Wide -AutoSize
$Headerstring = '<?xml version="1.0"?>'
$Headerstring | Out-File $filename
if ($outputType -eq "Text")
{
$DataSet.Tables[0] | Format-Table -HideTableHeaders -autosize -Wrap | out-file $filename -Encoding utf8
}
Output file (the first line is the problem because I need to make this script):
<?xml version="1.0"?>
<publicacoes>
<publicacao>
<codigo>1111111</codigo>
<rec_id>2022/06/28 08:26</rec_id>
<data_publicacao>2022/06/28 00:00</data_publicacao>
<pacote>Lorem ipsum dolor sit amet</pacote>
<caderno>Lorem ipsum dolor sit amet</caderno>
<pesquisa>Lorem ipsum dolor sit amet</pesquisa>
<detalhamento>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</detalhamento>
<processo>11111111111111</processo>
<pagina>null</pagina>
<texto>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</texto>
</publicacao>
</publicacoes>

Answer 1

So, you've clearly dummied out your SQL query partially. That's fine, but it means I'm guessing here and you'll have to account for that.
I am assuming your output has a single column of output, since that's typically how FOR XML works. The core problem here is likely that SQL Server assigns a random column name to the output when you're using FOR XML, and your Powershell script needs to know the column name.
First I'd change your SQL query to something like:
$Query = #'
SELECT (
SELECT *
FROM TableName
WHERE Condition = 1
FOR XML PATH ('Foo'), ROOT ('Bar')
) AS XmlOutput
'#
That will give your query output a fixed name.
Then you do this:
$DataSet.Tables[0].XmlOutput | Add-Content $FileName -Encoding utf8
I would avoid Out-File in favor of Set-Content because in some versions of Powershell it can have issues with truncating long lines.
Also, be aware that utf8 encoding includes a byte order mark. That's valid according to the Unicode spec, but lots of systems don't like it especially on Linux. If you're on Powershell v6+ you can specify -Encoding utf8nobom, but Windows Powershell v5.1 and earlier don't have that option.