Comment on XPath operators

Dear SPARQL WG,

For medical applications such as guideline-based decision support, 
clinical trial recruitment or the calculation of clinical quality 
indicators, it is often necessary to select patients with a certain age 
at a certain moment; e.g. "select all patients older than 18". To 
retrieve those patients, the current (or some other) date needs to be 
subtracted from the patient's date of birth. This is currently not 
possible in SPARQL.

Some XPath Arithmetic operators for numeric types are already included 
in the SPARQL Working Draft. To enable full usage of the type 
xsd:dateTime, could you also include the operators on durations, dates 
and times from the XQuery 1.0 and XPath 2.0 Functions and Operators 
Recommendation?

The most important one for the use-case above would be:
op:subtract-dateTimes($arg1 as xs:dateTime, $arg2 as xs:dateTime) as 
xs:dayTimeDuration.

Best regards,
Kathrin Dentler



-- 

Kathrin Dentler

AI Department         |   Department of Medical Informatics
Faculty of Sciences   |   Academic Medical Center
Vrije Universiteit    |   Universiteit van Amsterdam
k.dentler@vu.nl       |   k.dentler@amc.uva.nl

http://www.few.vu.nl/~kdr250/

Received on Wednesday, 20 July 2011 06:35:30 UTC