tags:

views:

54

answers:

3
Q: 

Using not() in XPath

Hi!

I would like how to use the "not" in XPath properly. I just can't seem to get it to work with attributes.

Say I have this expression: //*[@name = 'Bob'] It is valid, and will return all nodes that have a name attribute equaling 'Bob'.

Now if I want all nodes that have a name attribute that do not equal 'Bob', I need to use an XPath such as: //*[@name not(='Bob')] but this is invalid.

I have tried multiple combinations with not() being placed in a different order, but I can't seem to get this to work. Could someone please inform me how to use not() properly?

Also, does the order change when using elements instead of attributes? Such as: //name[text() = 'Bob']

Thanks! :)

+1  A: 

Try

 //*[@name != 'Bob']

or

  //*[not(@name = 'Bob')]

should work both.

Doc Brown  2010-08-05 19:37:15
@Doc Brown: This method works for numerical values but not for string values. //*[@numerical != 1] works. //*[@string != "someString"] does not. Only the root element is being returned!
developer  2010-08-05 21:19:34
I am pretty sure that this will work for strings. Sure you did not make an error, for example, wrong case? The comparison is case-sensitive.
Doc Brown  2010-08-06 14:24:29
@Doc Brown: yes I tried various searches. I am only getting the root node returned. :S
developer  2010-08-06 14:57:56
Please post a complete example, a small XML file and the XPATH you are really trying, then we shall see further.
Doc Brown  2010-08-06 16:08:38
@Doc Brown: I think there is an issue with my XSL code, but it only became apparent to me once I used !=. I did some further testing, and found the searches do not go through entire hierarchy. I posted a new question as I still can't fix it. http://stackoverflow.com/questions/3451325/xpath-results-from-xslt-are-incorrect-not-going-through-entire-xml
developer  2010-08-10 16:49:17
+3  A:  
//*[@name and @name != 'Bob']
John Kugelman  2010-08-05 19:38:30
Doesn't this give all elements whether they have @name or not? I need it to be an element with @name and then have it not equal 'Bob'
developer  2010-08-05 19:52:28
OK updated to check for existence of `@name`
John Kugelman  2010-08-05 20:00:17
@John Kugelman: I think just //*[@name != 'Bob'] would work.. as others suggested.BUT This method works for numerical values but not for string values. //*[@numerical != 1] works. //*[@string != "someString"] does not. Only the root element is being returned!
developer  2010-08-05 21:19:11
@John Kugelman: Sorry, it is my understanding that your solution does in fact work. I think there is an issue with my XSL code, but it only became apparent to me once I used !=. I did some further testing, and found the searches do not go through entire hierarchy. I posted a new question as I still can't fix it. http://stackoverflow.com/questions/3451325/xpath-results-from-xslt-are-incorrect-not-going-through-entire-xml
developer  2010-08-10 16:51:11
+1  A: 

According to : http://msdn.microsoft.com/en-us/library/ms256086.aspx, have you tried 

//*[@name != 'Bob']
mathieu  2010-08-05 19:38:47
@mathieu: I would be better to quote the specs (not MS documentation), from http://www.w3.org/TR/xpath/#booleans *"If one object to be compared is a node-set and the other is a string, then the comparison will be true if and only if there is a node in the node-set such that the result of performing the comparison on the string-value of the node and the other string is true"*
Alejandro  2010-08-05 20:10:19
@mathieu: This method works for numerical values but not for string values. //*[@numerical != 1] works. //*[@string != "someString"] does not. Only the root element is being returned!
developer  2010-08-05 21:20:17
@iHeartGreek: Did you try this? This is correct, beside the quot from MS...
Alejandro  2010-08-05 23:43:14
@Alejandro: I did, but it only works for numerical values, not string values like I mentioned above. With the string value, the only result I get is the root node.
developer  2010-08-06 14:57:16
@iHeartGreek: This works. Other order comparison operators (like >) only works for numbers (in XPath 2.0 you could use `op:gt` that works with collations).
Alejandro  2010-08-06 15:45:03
@Alejandro: I don't know what the problem could be then.. it doesn't work in the implementation I have. What could be possible sources of the problem?
developer  2010-08-06 16:45:31
@iHeartGreek: Ask other question with input sample, desired output and in progress stylesheet, and someone could answer that to you. Meanwhile, you should mark this as answer, I think.
Alejandro  2010-08-06 17:06:11
@Alejandro: ok, I selected it as the answer. I will try to ask another question next week.
developer  2010-08-06 19:39:48
@Alejandro: I think there is an issue with my XSL code, but it only became apparent to me once I used !=. I did some further testing, and found the searches do not go through entire hierarchy. I posted a question as I still can't fix it. http://stackoverflow.com/questions/3451325/xpath-results-from-xslt-are-incorrect-not-going-through-entire-xml
developer  2010-08-10 16:48:21

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