Avoiding Unicode issues when inserting XML into a SQL Database

December 29, 2010

If you have to insert XML into a SQL Server (2005+) XML column, there’s three ways of doing it.

Perform a raw string insert, which is unlikely to work
Use an XmlReader and SqlDbType.Xml
Use SqlDbType.Text and a Stream.

Below is my preferred way of doing it and gets around the problem you might come up with:

XML parsing: line 1, character (xx),
unable to switch the encoding

This occurs when you’re trying to shove a UTF8 string into the database XML column, using

<?xml version="1.0" encoding="utf-8"?>

It might also happen with a file with no BOM, which can be fixed by opening + saving the file in notepad. Anyway the solution below gets around this issue.

	using System.IO;
	using System.Text;
	using System.Data;
	using System.Data.SqlClient;
	using System.Data.SqlTypes;
	...
	using (SqlConnection connection = new SqlConnection("conn string"))
	{
	connection.Open();
	string sql = "INSERT INTO mytable (xmlColumn) VALUES (@xmlData)";
	using (SqlCommand command = new SqlCommand(sql, connection))
	{
	// Swap round if the source file is unicode
	string xml = File.ReadAllText(@"C:\myxml.xml");
	//string xml = File.ReadAllText(@"C:\myxml.xml", Encoding.Unicode);

	using (MemoryStream stream = new MemoryStream())
	{
	using (StreamWriter writer = new StreamWriter(stream, Encoding.Unicode))
	{
	writer.Write(xml);
	writer.Flush();
	stream.Position = 0;

	SqlParameter parameter = new SqlParameter("@xmlData", SqlDbType.Text);
	parameter.Value = new SqlXml(stream);
	command.Parameters.Add(parameter);
	command.ExecuteNonQuery();
	}
	}
	}
	}

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sql-serverxml

I'm Chris Small, a software engineer working in London. This is my tech blog. Find out more about me via Github, Stackoverflow, Resume