[xquery-talk] return only latest version of an item

[G. Ken Holman]

At 2009-05-14 14:18 -0400, A. Steven Anderson wrote:
>I've got a pretty complex xquery that returns only the latest 
>version of all items in a collection, but I know there has got to be 
>a more efficient way to do it.
>...
>What would be the most efficient way to do this?

By which criteria are you trying to measure efficiency?

Below is an example using max()

I hope this helps.

. . . . . . . . Ken

t:\ftemp>type steven.xml
<items>
    <item>
       <id>1</id>
       <name>item # 1</name>
       <version>1</version>
    </item>
    <item>
       <id>1</id>
       <name>item # 1</name>
       <version>2</version>
    </item>
    <item>
       <id>1</id>
       <name>item # 1</name>
       <version>3</version>
    </item>
    <item>
       <id>2</id>
       <name>item # 2</name>
       <version>1</version>
    </item>
    <item>
       <id>2</id>
       <name>item # 2</name>
       <version>2</version>
    </item>
    <item>
       <id>3</id>
       <name>item # 3</name>
       <version>1</version>
    </item>
</items>

t:\ftemp>type steven.xq
/items/item[version=max(/items/item/version)]


t:\ftemp>xquery steven.xml steven.xq con
<?xml version="1.0" encoding="UTF-8"?>
<item>
       <id>1</id>
       <name>item # 1</name>
       <version>3</version>
    </item>
t:\ftemp>

--
XQuery/XSLT/XSL-FO hands-on training - Los Angeles, USA 2009-06-08
Crane Softwrights Ltd.          http://www.CraneSoftwrights.com/q/
Training tools: Comprehensive interactive XSLT/XPath 1.0/2.0 video
Video lesson:    http://www.youtube.com/watch?v=PrNjJCh7Ppg&fmt=18
Video overview:  http://www.youtube.com/watch?v=VTiodiij6gE&fmt=18
G. Ken Holman                 mailto:gkholman at CraneSoftwrights.com
Male Cancer Awareness Nov'07  http://www.CraneSoftwrights.com/q/bc
Legal business disclaimers:  http://www.CraneSoftwrights.com/legal