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[Wei Cheng <We...@baylor.edu>]

Hi Gary,

Thursday, November 09, 2000, 10:14:42 PM, you wrote:

GLP> Wei Cheng wrote:
>> 
>> Hi All,
>>  I have tried to use Xalan package to do my master's project.
>>  First, I write a primary key fuction to try to test whether XMl
>>  document can satisfy the primary key requirement.
>>  I modify the example ApplyXpath.java and foo.xml to test my idea.
>>  I use foo1.xml as an XMl document input.
>>  ...

GLP> Wei --

GLP> Did you ever get an answer on this?  If you're trying to do this compare
GLP> in java, I think you can just iterate over the NodeSets with one loop
GLP> nested inside the other.

GLP> BTW, I'd stay away from NodeSet because this is a Xalan invention that
GLP> could change.  NodeSet also extends NodeList which is a DOM class and I
GLP> think you'd be better off using that or NodeIterator.

GLP> You could also do this entirely with your XPath.  You currently have the
GLP> second XPath as 

GLP>         /doc/name[1]/following-sibling::name/firstname

GLP> I think you could make it something like

GLP>         /doc/name[1]/following-sibling::name/firstname[. !=
GLP> /doc/name[1]/firstname]

GLP> Then, you'd only have one XPath and you'd just have to check if the
GLP> resulting node-set was null or not.  If you wanted, you could loop
GLP> through this for each name in doc and dynamically build an XPath,
GLP> changing the subscript in your java program.

GLP> Or, you could use XPath alone to just get a node-set containing all of
GLP> the name elements that contain what you call primary keys:

GLP>         /doc/name[firstname != preceding-sibling::name/firstname]

GLP> Haven't tested these expressions, but they should be close.

GLP> Gary

   Thanks a lot first! I have tried all these two expressions, for the
   second one   /doc/name[firstname !=
   preceding-sibling::name/firstname],
   it seems that I can't get the /doc/name[1]/firstname when I apply
   Xpath, I want to test a set of firstname in the doc to see whether
   all firstname are different,if yes,I return yes otherwise return
   false.
   this is my strategy:
   If I can get NodeIterator when I apply second Xpath, and
   compare with another NodeIterator when I apply /doc/name/firstname,
   and I compare each node in these two nodeiterators, to see if the node
   order and the value is the same, then return true else false.
   but for some reason, /doc/name[1]/firstname doesn't show in the
   nodeiterator when I apply second Xpath from you. From the
   definition,it should be here. because the /doc/name[1]/firstname's
   preceding-sibling should be null.
   Can you give me some advice on this or give me other idea for this?
   Thanks again!

Best regards,
 Wei                            mailto:Wei_Cheng@baylor.edu