How to export XML using a SQL Server query? - sql-server-2008

Question

Let's say I have a table Employee like this
EmpID, EmpName
1 , hatem
and I write a query: select * from Employee for xml auto
so the output will be in XML format.
I want to know how can I export the result to a XML file to be saved on my computer's drive as I need to read the XML files from this folder and deserialize them in my .net application.

Answer 1

If you only need to store the XML and not do anything else to it, this is probably the easiest way to accomplish this - using straight simple ADO.NET:
string query = "SELECT EmployeeID, LastName, FirstName, Title, BirthDate, HireDate FROM dbo.Employees FOR XML AUTO";
using(SqlConnection _con = new SqlConnection("server=(local);database=Northwind;integrated security=SSPI;"))
using (SqlCommand _cmd = new SqlCommand(query, _con))
{
_con.Open();
string result = _cmd.ExecuteScalar().ToString();
_con.Close();
File.WriteAllText(#"D:\test.xml", result);
}
This will create a file D:\test.xml (or change that to match your system) and will put those XML tags into that file.
The SqlCommand object also has a .ExecuteXmlReader() method which would return an XmlReader object to scan and manipulate the XML - not just return a string. Use whatever makes the most sense to you!
PS: also, the output of FOR XML AUTO is a bit .... let's say ... suboptimal. It uses the dbo.Employee as it's main XML tag and so forth... with SQL Server 2008, I would strongly recommend you look into using FOR XML PATH instead - it allows you to tweak and customize the layout of the XML output.
Compare your original XML output with FOR XML AUTO
<dbo.Employees _x0040_ID="1" LastName="Davolio" FirstName="Nancy" Title="Sales Representative" BirthDate="1948-12-08T00:00:00" HireDate="1992-05-01T00:00:00" />
<dbo.Employees _x0040_ID="2" LastName="Fuller" FirstName="Andrew" Title="Vice President, Sales" BirthDate="1952-02-19T00:00:00" HireDate="1992-08-14T00:00:00" />
against this query - just to see the difference:
SELECT
[EmployeeID] AS '#ID',
[LastName], [FirstName],
[Title],
[BirthDate], [HireDate]
FROM
[dbo].[Employees]
FOR XML PATH('Employee'), ROOT('Employees')
Output is:
<Employees>
<Employee ID="1">
<LastName>Davolio</LastName>
<FirstName>Nancy</FirstName>
<Title>Sales Representative</Title>
<BirthDate>1948-12-08T00:00:00</BirthDate>
<HireDate>1992-05-01T00:00:00</HireDate>
</Employee>
<Employee ID="2">
<LastName>Fuller</LastName>
<FirstName>Andrew</FirstName>
<Title>Vice President, Sales</Title>
<BirthDate>1952-02-19T00:00:00</BirthDate>
<HireDate>1992-08-14T00:00:00</HireDate>
</Employee>

Answer 2

I've had the same problem and I've created a .NET CLR that exports XML to a file:
using System;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;
using System.Text;
using System.Xml;
using System.IO;
public sealed class StringWriterWithEncoding : StringWriter
{
private readonly Encoding encoding;
public StringWriterWithEncoding(Encoding encoding)
{
this.encoding = encoding;
}
public override Encoding Encoding
{
get { return encoding; }
}
}
public partial class StoredProcedures
{
[Microsoft.SqlServer.Server.SqlProcedure]
public static void XMLExport (SqlXml InputXml, SqlString OutputFile)
{
try
{
if (!InputXml.IsNull && !OutputFile.IsNull)
{
XmlDocument doc = new XmlDocument();
doc.LoadXml(InputXml.Value);
StringWriterWithEncoding sw = new StringWriterWithEncoding(System.Text.Encoding.UTF8);
XmlWriterSettings settings = new XmlWriterSettings
{
Indent = true,
IndentChars = " ",
NewLineChars = "\r\n",
NewLineHandling = NewLineHandling.Replace,
Encoding = System.Text.Encoding.UTF8
};
using (XmlWriter writer = XmlWriter.Create(sw, settings))
{
doc.Save(writer);
}
System.IO.File.WriteAllText(OutputFile.ToString(), sw.ToString(), System.Text.Encoding.UTF8);
}
else
{
throw new Exception("Parameters must be set");
}
}
catch
{
throw;
}
}
}
Here's an example how to use it:
DECLARE #x xml
SET #x = '<Test><Something>1</Something><AnotherOne>2</AnotherOne></Test>'
EXEC dbo.XmlExport #x, 'c:\test.xml'
And the output is a nicely formatted XML file:
<?xml version="1.0" encoding="utf-8"?>
<Test>
<Something>1</Something>
<AnotherOne>2</AnotherOne>
</Test>