How to select xml node from node data using c#

Question

I have an XML whose data looks like

<Chart>
<History>
<Master_Medication_List>
<Item1>
<ndcnumber>00121478105</ndcnumber>
</Item1>
</Master_Medication_List>
</History>
</Chart>

Now I want to select node for that using this code

objEncList = objXml.SelectNodes("//Chart/History/Master_Medication_List/Item1/*[ndcnumber='" + strProductCode + "']");

but it's not selecting any node.

is strProductCode is your ndcnumber right? – Silence Peace Jun 07 '16 at 18:48 — Silence Peace, Jun 07 '16 at 18:48
yes strProductCode = 00121478105 – saudblaze Jun 07 '16 at 19:06 — saudblaze, Jun 07 '16 at 19:06
No its not case sensitive error . – saudblaze Jun 07 '16 at 19:07 — saudblaze, Jun 07 '16 at 19:07

score 0 · Answer 1 · answered Jun 07 '16 at 19:15

It's an element, so you would just access it like:

objEncList = objXml.SelectNodes("//Chart/History/Master_Medication_List/Item1/ndcnumber");

That is the node, the node's value is the actual value.

If you have multiple Item1s, I think you can select it via:

objEncList = objXml.SelectNodes("//Chart/History/Master_Medication_List/Item1/ndcnumber[text()='00121478105']");

score 0 · Accepted Answer · answered Jun 07 '16 at 19:17

You want to select the element by content. ndcnumber[.='content'] is how you do that. So either

objEncList = objXml.SelectNodes("
    //Chart/History/Master_Medication_List/Item1/ndcnumber[.='" + strProductCode + "']"
);

Or, if objXml is the actual root already, omit it:

objEncList = objXml.SelectNodes("
    /History/Master_Medication_List/Item1/ndcnumber[.='" + strProductCode + "']"
);

dbc · Answer 3 · 2016-06-07T19:25:55.960

If you are looking to select all <Item1> elements with a nested <ndcnumber> element with value 00121478105, you should do:

var itemList = objXml.SelectNodes("//Chart/History/Master_Medication_List/Item1[ndcnumber='" + strProductCode + "']");

If you are looking to select all <ndcnumber> elements with value 00121478105, you should do:

var ndcnumberList = objXml.SelectNodes("//Chart/History/Master_Medication_List/Item1/ndcnumber[text()='" + strProductCode + "']");

(It is unclear from your question which you want.)

Notes:

XPath queries are case sensitive, so you need to match the element name exactly.
You have one too many levels in your query string: Item1/*[ndcnumber=... means "Look for any child of Item1 with a child named ndcnumber with a specific value.
If strProductCode is a user-entered string, watch out for XPath injection attacks. See XPath injection mitigation and How to prevent XPath/XML injection in .NET.

Example fiddle.

3 Answers3