XPATH Multiple Element Filters

CroweMan picture CroweMan · Jan 23, 2009 · Viewed 64k times · Source

I have the following sample XML structure:

<SavingAccounts>
    <SavingAccount>
       <ServiceOnline>yes</ServiceOnline>
       <ServiceViaPhone>no</ServiceViaPhone>
    </SavingAccount>
    <SavingAccount>
       <ServiceOnline>no</ServiceOnline>
       <ServiceViaPhone>yes</ServiceViaPhone>
    </SavingAccount>
</SavingAccounts>

What I need to do is filter the 'SavingAccount' nodes using XPATH where the value of 'ServiceOnline' is 'yes' or the value of 'ServiceViaPhone' is yes.

The XPATH should return me two rows!! I can filter 'SavingAccount' nodes where both of the element values are yes like the following XPATH sample, but what I want to do is an or element value comparison???

/SavingAccounts/SavingAccount/ServiceOnline[text()='yes']/../ServiceViaPhone[text()='yes']/..

Answer

Dimitre Novatchev picture Dimitre Novatchev · Jan 23, 2009

This is a very fundamental XPath feature: composing a number of conditions with the logical operators and, or, and the function not().

and has a higher priority than or and both operators have lower priority than the relational and equality operators (=, !=, >, >=, &lt; and &lt;=).

So, it is safe to write: A = B and C = D

Some most frequent mistakes made:

  1. People write AND and/or OR. Remember, XPath is case-sensitive.

  2. People use the | (union) operator instead of or

Lastly, here is my solution:

/SavingAccounts/SavingAccount
           [ServiceOnLine='yes' or ServiceViaPhone='yes']