How to filter XML elements using LINQ query for one attribute/field containing a particular substring?

Question

Example:

<Item name="item1">
    <mode = "ax, bx" />
</Item>
<Item name="item2">
    <mode = "bx, cx" />
</Item>
<Item name="item3">
    <mode = "cx, dx" />
</Item>

In the example above I would like to extract all the items with modes containing "cx".

Thanks in advance!

Thank you for all your answers. Seems to me all of you are right, so I'll just select the first one that answered and +1 to each. — Ronald, Nov 29 '11 at 14:41

score 2 · Accepted Answer · answered Nov 29 '11 at 13:50

2

Your XML in the example is not well formed. Assuming you meant:

<Items>
  <Item name="item1">
    <mode>ax, bx</mode>
  </Item>
  <Item name="item2">
    <mode>bx, cx</mode>
  </Item>
  <Item name="item3">
    <mode>cx, dx</mode> 
  </Item>
</Items>

you can do:

var els=from el in XDocument.Parse(inxml).Descendants("Item")
where el.Element("mode").Value.Contains("bx")
select el;

answered Nov 29 '11 at 13:50

Paolo Falabella

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what is `inxml` here in your answer it is giving me error while writing the query `Error 1 Could not find an implementation of the query pattern for source type 'System.Collections.Generic.IEnumerable'. 'Where' not found. Are you missing a reference to 'System.Core.dll' or a using directive for 'System.Linq'? D:\RND\TinyMce\Default.aspx.cs 148 30 D:\RND\TinyMce\ ` – Murtaza Mar 07 '12 at 13:10
it's a string containing your xml – Paolo Falabella Mar 07 '12 at 13:17
also, looking at the error you get, seems you should add `using System.Linq; using System.Xml.Linq;` – Paolo Falabella Mar 07 '12 at 15:56
I have already added the reference of the above two namespaces. – Murtaza Mar 09 '12 at 04:19

score 1 · Answer 2 · answered Nov 29 '11 at 13:50

That is not legal XML (mode is an element name, you can set it equal to a string), but you should be able to do something like this, assuming that the string you are matching is the element value:

doc.Descendants("Item").Where( item => item.Elements("mode").Any( mode => mode.Value.Contains("cx")));

score 1 · Answer 3 · answered Nov 29 '11 at 14:10

Assuming a well formed XML doc:

<Items>
  <Item name="item1">
    <mode>ax, bx</mode>
  </Item>
  <Item name="item2">
    <mode>bx, cx</mode>
  </Item>
  <Item name="item3">
    <mode>cx, dx</mode> 
  </Item>
</Items>

Do something like this:

XElement items = XElement.Load(@"C:\items.xml");

var filteredItems = from item in items.Descendants("Item")
            where item.Element("mode").Value.Contains("cx")
            select item;

foreach (var item in filteredItems)
{
    Console.WriteLine(item.FirstAttribute.Value);
}

Output:

item2
item3

How to filter XML elements using LINQ query for one attribute/field containing a particular substring?

3 Answers3