SQL Select XML from table like serialized Dictionary<string, object) - sql

Question

I have an XML structure that I got by serializing a Dictionary in C#. I'm doing this to add one AdditionalSettings column to a table versus multiple additional columns and this works great.
The XML structure is like this:
<Settings xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<Setting>
<Name>Setting1</Name>
<Value xmlns:d3p1="http://www.w3.org/2001/XMLSchema" i:type="d3p1:boolean">true</Value>
</Setting>
<Setting>
<Name>Setting2</Name>
<Value xmlns:d3p1="http://www.w3.org/2001/XMLSchema" i:type="d3p1:boolean">true</Value>
</Setting>
The table has several columns like this:
ID (INT)
Setting1 (BIT)
Setting2 (BIT)
I think I am close to a solution. This is the SQL that I have. The problem is that I am not getting the namespaces on the Value element.
WITH XMLNAMESPACES ('http://www.w3.org/2001/XMLSchema-instance' AS i)
SELECT TOP 1 'Setting1' AS [Setting/Name],
CASE Setting1 WHEN 1 THEN 'true' ELSE 'false' END AS [Setting/Value]
FROM MyTable
FOR XML PATH('Settings')
The output of this SQL looks like this:
<Settings xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<Setting>
<Name>Setting1</Name>
<Value>true</Value>
</Setting>
</Settings>
EDIT: Instead of doing SQL for a fake table, I've created SQL for a Temp Table that shows what I am trying to do.
DECLARE #TestTable TABLE (ID INT IDENTITY(1, 1) PRIMARY KEY, [Name] VARCHAR(10), Setting1 BIT, Setting2 BIT)
INSERT INTO #TestTable (Name, Setting1, Setting2)
VALUES
('Test1', 0, 0),
('Test2', 0, 1),
('Test3', 1, 0),
('Test4', 1, 1);
WITH XMLNAMESPACES ('http://www.w3.org/2001/XMLSchema-instance' AS i)
SELECT TOP 1 'Setting1' AS [Setting/Name],
CASE Setting1 WHEN 1 THEN 'true' ELSE 'false' END AS [Setting/Value]
FROM #TestTable
WHERE Setting1 = 1
FOR XML PATH('Settings')

Answer 1

Try changing:
AS [Setting/Value]
To be:
AS 'i:value'
e.g.
WITH XMLNAMESPACES ('http://www.w3.org/2001/XMLSchema-instance' AS i)
SELECT TOP 1 'Setting1' AS 'i:name',
CASE Setting1 WHEN 1 THEN 'true' ELSE 'false' END AS 'i:value'
FROM MyTable
FOR XML PATH('Settings')

Answer 2

I finally gave up trying to find a way to do this with a SQL Query, though if anyone does figure this out I am still interested to know the answer.
What I ended up doing was to write a C# Windows Forms application (because I like to launch the code I want with a button as opposed to a more common console application).
The code for this is as follows if anyone is interested.
This is the AdditionalSettings class.
[System.Runtime.Serialization.CollectionDataContract(Namespace = "", Name = "Settings", ItemName = "Setting", KeyName = "Name", ValueName = "Value")]
public class AdditionalSettings : Dictionary<string, object>
{
}
The code is below:
using System;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Text;
using System.Windows.Forms;
namespace PopulateSettings
{
public partial class frmMain : Form
{
public frmMain()
{
InitializeComponent();
}
private void btnDoThis_Click(object sender, EventArgs e)
{
DataTable sources = GetSettings();
foreach (DataRow dr in sources.Rows)
{
AdditionalSettings settings = new AdditionalSettings();
int settingID = (int)dr["SettingID"];
bool setting1 = dr["Setting1"] == DBNull.Value ? false : (bool)dr["Setting1"];
bool setting2 = dr["Setting2"] == DBNull.Value ? false : (bool)dr["Setting2"];
bool setting3 = (int)dr["Setting3"] == 0 ? false : true;
bool setting4 = dr["Setting4"] == DBNull.Value ? false : (bool)dr["Setting4"];
AddToDictionary(settings, "Setting1", setting1);
AddToDictionary(settings, "Setting2", setting2);
AddToDictionary(settings, "Setting3", setting3);
AddToDictionary(settings, "Setting4", setting4);
string additionalSettings = Serialize<AdditionalSettings>(settings);
UpdateSources(settingID, additionalSettings);
}
}
private DataTable GetSettings()
{
DataTable settings = null;
string sqlString = #"SELECT SettingID, Setting1, Setting2, Setting3, Setting4
FROM dbo.Settings
WHERE Setting1 = 1
OR Setting2 = 1
OR Setting3 = 1
OR Setting4 = 1";
using (var cnMy = new SqlConnection(ConfigurationManager.AppSettings["MyConnectionString"]))
{
using (var cmd = new SqlCommand(sqlString, cnMy))
{
cmd.CommandType = CommandType.Text;
cnMy.Open();
using (var da = new SqlDataAdapter(cmd))
{
settings = new DataTable();
da.Fill(settings);
}
}
}
return settings;
}
private void AddToDictionary(AdditionalSettings dictionary, string name, bool setting)
{
if (setting)
{
dictionary.Add(name, setting);
}
}
public string Serialize<T>(T Data)
{
string strXML = System.String.Empty;
System.Xml.XmlWriterSettings xmlWriterSettings = new System.Xml.XmlWriterSettings();
xmlWriterSettings.OmitXmlDeclaration = true;
xmlWriterSettings.NamespaceHandling = System.Xml.NamespaceHandling.OmitDuplicates;
xmlWriterSettings.Indent = true;
var serializer = new System.Runtime.Serialization.DataContractSerializer(typeof(T));
System.Text.StringBuilder sbXML = new StringBuilder();
using (System.IO.StringWriter oStringWriter = new System.IO.StringWriter(sbXML))
{
using (System.Xml.XmlWriter xmlWriter = System.Xml.XmlWriter.Create(oStringWriter, xmlWriterSettings))
{
serializer.WriteObject(xmlWriter, Data);
xmlWriter.Flush();
}
strXML = sbXML.ToString();
}
return strXML;
}
private void UpdateSources(int settingID, string additionalSettings)
{
string sqlString = #"UPDATE dbo.Settings SET AdditionalSettings = #AdditionalSettings WHERE SettingID = #SettingID";
using (var cnMy = new SqlConnection(ConfigurationManager.AppSettings["MyConnectionString"]))
{
using (var cmd = new SqlCommand(sqlString, cnMy))
{
cmd.CommandType = CommandType.Text;
cmd.Parameters.Clear();
cmd.Parameters.Add("#AdditionalSettings", SqlDbType.VarChar).Value = additionalSettings;
cmd.Parameters.Add("#SettingID", SqlDbType.Int).Value = settingID;
cnMy.Open();
cmd.ExecuteNonQuery();
}
}
}
}
}