Seemingly simple LINQ to XML query? RSS

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  InternetH3ro

  Member

  83 Points

  65 Posts

  Seemingly simple LINQ to XML query?

  Mar 18, 2008 07:50 PM|LINK

  Hey all, I have what I think should be a simple LINQ to XML query, but I'm not getting any results in my enumeration.

  Here's my XML:

   

  <Collection>
     <Artist ID="1" Name="Dream Theater">
        <Member ID="1" Name="John Petrucci" />
        <Member ID="2" Name="Mike Portnoy" />
     </Artist>
     <Artist ID="2" Name="Opeth">
        <Member ID="3" Name="Mikael Akerfeldt" />
        <Member ID="4" Name="Martin Mendez" />
     </Artist>
     <Artist ID="3" Name="Porcupine Tree">
        <Member ID="5" Name="Steven Wilson" />
        <Member ID="6" Name="Gavin Harrison" />
     </Artist>
  </Collection>

  The query I am trying to run is to get all the <Member> elements of an artist with a given ID.  This is the query I have (I have a Member class):

   

  string artistID = ddlArtists.SelectedValue;
  var members = from artist in this._xDoc.Elements("Artist")
                where artist.Attribute("ID").Value == artistID.ToString()
                select new Member
                {
                   MemberID = Convert.ToInt32(artist.Element("Member").Attribute("ID").Value),
                   MemberName = artist.Element("Member").Attribute("Name").Value,
                   MemberInstrument = artist.Element("Member").Attribute("Instrument").Value
                };

  However, my result enumeration contains no elements.  Am I doing something wrong?  Is there an easier way to get a collection of Member objects for an artist with a given ID value?  Thanks for any and all help.  I've scoured the web for LINQ to XML examples and haven't come up with a proper solution as of yet, though I will continue to bang my head against this.

   
  James
  
   

  ASP.NET 3.5 Extensions LINQ LINQ : Return Value

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  bitmask

  Contributor

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  Re: Seemingly simple LINQ to XML query?

  Mar 19, 2008 05:29 PM|LINK

  James:

  The Element method is looking for child elements, so try using:

  
  <div style="BORDER-RIGHT: black 1pt solid; BORDER-TOP: black 1pt solid; FONT-SIZE: 8pt; BORDER-LEFT: black 1pt solid; BORDER-BOTTOM: black 1pt solid; FONT-FAMILY: monospace; BACKGROUND-COLOR: #d3d3bd">var members =
      from artist in xdoc.Elements("Collection").Elements("Artist")
      where artist.Attribute("ID").Value == artistID.ToString()
      select new
      {
          MemberID = Convert.ToInt32(artist.Element("Member").Attribute("ID").Value),
          MemberName = artist.Element("Member").Attribute("Name").Value
  
      };
  </div>

  or

  <div style="BORDER-RIGHT: black 1pt solid; BORDER-TOP: black 1pt solid; FONT-SIZE: 8pt; BORDER-LEFT: black 1pt solid; BORDER-BOTTOM: black 1pt solid; FONT-FAMILY: monospace; BACKGROUND-COLOR: #d3d3bd">var members =
      from artist in xdoc.Descendants("Artist")
      where artist.Attribute("ID").Value == artistID
      select new
      {
          MemberID = Convert.ToInt32(artist.Element("Member").Attribute("ID").Value),
          MemberName = artist.Element("Member").Attribute("Name").Value,
  };
  </div>

  Hope that helps,

  Scott
  http://www.OdeToCode.com/blogs/scott/
  http://twitter.com/OdeToCode