PowerShell and SQL Server – Exporting Data (XML)

Sometimes it can be useful to export data from a database, so that it can be analysed, or, to import in to another computer system. XML or eXtensible Markup Language files are an alternative file format to CSV, that can sometimes be used for both of these scenarios.

The example below exports data from a table called ‘person’, which contains five columns, ‘id’, ‘firstname’, ‘lastname’, ‘title’ and ‘dob’, from within an SQL Server database, to a XML file in a specified location.

id firstname lastname title dob
1 Bob Smith Mr 1980-01-20
3 Fred Bloggs Mr 1975-05-07
4 Alan White Mr 1989-03-20
5 Fiona Bloggs Mrs 1985-05-19
6 Zoe Davis Miss 1979-07-11
7 Tom Ingram Mr 1971-10-04
8 Karen Thomas Mrs 1969-03-08
9 Samantha Yates Miss 1995-08-27

Firstly, variables are defined to facilitate the connection and authentication to the database. This is followed by a query string to extract, or select, the data from the ‘person’ table, as well as variables for the XML file path and name. If the file path exists, the ‘Invoke-Sqlcmd’ cmdlet is used to extract the data. If data has been returned, a new XML file is created and its contents is constructed. Feedback is provided as to the success or failure of the task.

# Clear the console window.
Clear-Host

# Database variables.
$server = "localhost\MSSQLSERVERDEMO"
$database = "Demo"
$username = "DemoUN"
$password = "DemoPW"

# SQL query to select all data in the person table.
$query = "SELECT * FROM [dbo].[person] ORDER BY [id]"

# Export path and file.
$exportPath = "C:\Demo\"
$exportXml = "personexport.xml"

# Check to see if the file path exists.
if (Test-Path $exportPath)
{

    try
    {

        # Extract the data.
        $people = Invoke-Sqlcmd -ServerInstance $server -Database $database `
        -Username $username -Password $password -Query $query -ErrorAction Stop

        # If data has been returned, do the export.
        if ($people.Count -gt 0)
        {

            # Construct the full file path.
            $fullFilePath = $exportPath + $exportXml

            # Create the XML file.
            $xmlWriter = New-Object System.XMl.XmlTextWriter($fullFilePath,$Null)

            # Set the formatting for the document.
            $xmlWriter.Formatting = 'Indented'
            $xmlWriter.Indentation = 1
            $XmlWriter.IndentChar = "`t"

            # Add the declaration for the document.
            $xmlWriter.WriteStartDocument()

            # Add the root element.
            $xmlWriter.WriteStartElement('people')

            # Process the rows of data.
            foreach ($person in $people)
            {

                # Open the person element.
                $xmlWriter.WriteStartElement('person')

                # Add the person details.
                $xmlWriter.WriteElementString('id', $person.id)
                $xmlWriter.WriteElementString('firstname', $person.firstname)
                $xmlWriter.WriteElementString('lastname', $person.lastname)
                $xmlWriter.WriteElementString('title', $person.title)
                $xmlWriter.WriteElementString('dob', $person.dob)

                # Close the person element.
                $xmlWriter.WriteEndElement()

            }

            # Close the root XML element.
            $xmlWriter.WriteEndDocument()

            # Flush the internal buffer.
            $xmlWriter.Flush()

            # Close the XML document.
            $xmlWriter.Close()

            # Message stating export successful.
            Write-Host "Data export successful."

        }
        else
        {

            # Message stating no data to export.
            Write-Host "There is no data to export."
          
        }

    }
    catch
    {

        # Message stating export unsuccessful.
        Write-Host "Data export unsuccessful."

    }

}
else
{

    # Message stating file path does not exist.
    Write-Host "File path does not exist."

}

The XML file produced contains the following data. Note that, although dates in an SQL Server database are stored in the format YYYY-MM-DD (four digit year, two digit month and two digit day), they are output to XML in a day, month, year and time format.

<?xml version="1.0"?>
<people>
	<person>
		<id>1</id>
		<firstname>Bob</firstname>
		<lastname>Smith</lastname>
		<title>Mr</title>
		<dob>01/20/1980 00:00:00</dob>
	</person>
	<person>
		<id>3</id>
		<firstname>Fred</firstname>
		<lastname>Bloggs</lastname>
		<title>Mr</title>
		<dob>05/07/1975 00:00:00</dob>
	</person>
	<person>
		<id>4</id>
		<firstname>Alan</firstname>
		<lastname>White</lastname>
		<title>Mr</title>
		<dob>03/20/1989 00:00:00</dob>
	</person>
	<person>
		<id>5</id>
		<firstname>Fiona</firstname>
		<lastname>Bloggs</lastname>
		<title>Mrs</title>
		<dob>05/19/1985 00:00:00</dob>
	</person>
	<person>
		<id>6</id>
		<firstname>Zoe</firstname>
		<lastname>Davis</lastname>
		<title>Miss</title>
		<dob>07/11/1979 00:00:00</dob>
	</person>
	<person>
		<id>7</id>
		<firstname>Tom</firstname>
		<lastname>Ingram</lastname>
		<title>Mr</title>
		<dob>10/04/1971 00:00:00</dob>
	</person>
	<person>
		<id>8</id>
		<firstname>Karen</firstname>
		<lastname>Thomas</lastname>
		<title>Mrs</title>
		<dob>03/08/1969 00:00:00</dob>
	</person>
	<person>
		<id>9</id>
		<firstname>Samantha</firstname>
		<lastname>Yates</lastname>
		<title>Miss</title>
		<dob>08/27/1995 00:00:00</dob>
	</person>
</people>

 

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