Xml Linq, removing duplicate nodes in XElement C#

Question

I use Xml.Linq for manage xml configuration files.

I have XElement (Company.CalidadCodigo.ParserSQL.Reglas), and I need remove duplicate values in XElement (nodes Add-Key-Value, which Value is repeated).

I use Union but not right.

var reglasComunes = reglasParaTarget.Union(reglasParaSecundario);

Any sample code about it?

 <?xml version="1.0" encoding="utf-8"?>
    <configuration>
      <configSections>
        <section name="Company.CalidadCodigo.ParserSQL.Reglas" type="System.Configuration.NameValueSectionHandler" />
      </configSections>
      <appSettings></appSettings>
       <Company.CalidadCodigo.ParserSQL.Reglas>
    <add key="AnalisisSintactico" value="CalidadCodigo.ParserSQL.Reglas.AnalisisSintactico,CalidadCodigo.ParserSQL.AnalisisSintactico, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9744987c0853bf9e" />
    <add key="AnalisisRecomendaciones" value="CalidadCodigo.ParserSQL.Reglas.AnalisisRecomendaciones,CalidadCodigo.ParserSQL.AnalisisRecomendaciones, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9744987c0853bf9e" />
    <add key="FinFichero" value="CalidadCodigo.ParserSQL.Reglas.FinFichero,CalidadCodigo.ParserSQL.FinFichero, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9744987c0853bf9e" />
    <add key="CheckTree" value="CalidadCodigo.ParserSQL.Reglas.CheckTreeException,CalidadCodigo.ParserSQL.FinFichero, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9744987c0853bf9e" />
    <add key="AnalisisSintactico" value="CalidadCodigo.ParserSQL.Reglas.AnalisisSintactico,CalidadCodigo.ParserSQL.AnalisisSintactico, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9744987c0853bf9e" />
    <add key="Regla1" value="CalidadCodigo.ParserSQL.Reglas.Regla1,CalidadCodigo.ParserSQL.Regla1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9744987c0853bf9e" />
    <add key="Regla2" value="CalidadCodigo.ParserSQL.Reglas.Regla2,CalidadCodigo.ParserSQL.Regla2, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9744987c0853bf9e" />
    <add key="CheckTree" value="CalidadCodigo.ParserSQL.Reglas.CheckTreeException,CalidadCodigo.ParserSQL.FinFichero, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9744987c0853bf9e" />

  </Company.CalidadCodigo.ParserSQL.Reglas>
    </configuration>

Answer 1

Try group them into distinct values as follow:

XDocument doc = XDocument.Load(@"config.xml");
var query = from company in doc.Descendants("Company.CalidadCodigo.ParserSQL.Reglas")
   from keys in company.Descendants()
   group keys by keys.Attribute("value").Value into distinctResult
   select new { key = distinctResult.FirstOrDefault().Attribute("key").Value, value = distinctResult.Key };


foreach (var result in query)
 Console.WriteLine("key: " + result.key);

OUTPUT:

key: AnalisisSintactico
key: AnalisisRecomendaciones
key: FinFichero
key: CheckTree
key: Regla1
key: Regla2

Answer 2

Following gives you the distinct rows.

XDocument doc = new XDocument(new XElement("doc"
    , new XElement("add", new XAttribute("value", "11"))
    , new XElement("add", new XAttribute("value", "23"))
    , new XElement("add", new XAttribute("value", "22"))
    , new XElement("add", new XAttribute("value", "22"))
    , new XElement("add", new XAttribute("value", "22"))
    , new XElement("add", new XAttribute("value", "11"))));

//Select Distinct Rows, gives 11,23,22
var result =
    from row in doc.Descendants("add")
    group row by (string)row.Attribute("value") into g
    select g.First();