[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: Re: Constraints for nested elements; key and keyref

• To: "Henry S. Thompson"<ht@i...>,ea_6666@f...
• Subject: Re: Re: Constraints for nested elements; key and keyref
• From: ea_6666@f...
• Date: Tue, 01 Feb 2005 14:36:40 +0100
• Cc: xml-dev@l...

Hallo Henry, hallo all.

Thanks for your answer.
I changed my schema and added an attribute parentid to the element child.
Instantly a new question came up: How can I achieve it, that in one parent-element all parent-ids of the child elements are equal to 
the parentid of the parent?
One approach that I found is listed below; it is an additional element parentid. But I don't like this additional element; is there a 
possibility to do it without this element ?

Thanks in advance,

Erich


---- XML-Instance ----

<?xml version="1.0" encoding="UTF-8"?>
<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="Multikeys_v2.xsd">
	<parent parentid="1">
		<parentid parentid="1"/>
		<child parentid="1" childid="4711"/>
		<child parentid="1" childid="4712"/>
		<child parentid="1" childid="4713"/>
	</parent>
	<parent parentid="2">
		<parentid parentid="2"/>
		<child parentid="2" childid="4711"/>
		<child parentid="2" childid="4715"/>
	</parent>
	<refer>
		<parentRef parentRefId="1">
			<childRef  parentRefId="1" childRefId="4711"/>
		</parentRef>
		<parentRef parentRefId="2">
			<childRef  parentRefId="2" childRefId="4715"/>
		</parentRef>
	</refer>
</root>


----------------------------------------------
Erich Andresen,                                              ea_6666@f...

--- original Nachricht Ende ----


ea_6666@f... writes:

> I have several elements named 'parent' with an attribute named
> 'parentid' and subelements 'child' also with an attribute
> 'childid'. My intention (first part) is that each child is unique
> with respect to the childid in his parent and each parent is unique
> with respect to his parentid in the root element. This can be done
> by the two keys 'childKey' and 'parentKey'.  The second part of my
> intention is to reference in an later section of the xml-file to the
> childs, like it is show below.  The problem is to describe an
> appropiate keyref.

Sensible design, sensible question, but can't be done with the XML as
described, sorry.  Chained keyrefs, which is what you need, are a
candidate requirement for a subsequent version.

Meantime, only way to win is to copy parentid on to all children, then
use two-part key and keyref.

ht
-- 
 Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
                     Half-time member of W3C Team
    2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
            Fax: (44) 131 650-4587, e-mail: ht@i...
                   URL: http://www.ltg.ed.ac.uk/~ht/
[mail really from me _always_ has this .sig -- mail without it is forged spam]

-----------------------------------------------------------------
The xml-dev list is sponsored by XML.org <http://www.xml.org>, an
initiative of OASIS <http://www.oasis-open.org>

The list archives are at http://lists.xml.org/archives/xml-dev/

To subscribe or unsubscribe from this list use the subscription
manager: <http://www.oasis-open.org/mlmanage/index.php>

• Follow-Ups:
  • Re: Constraints for nested elements; key and keyref
    • From: ht@i... (Henry S. Thompson)

• Prev by Date: RE: What is coupling? [Was: 3 XML Design Principles]
• Next by Date: RE: What is coupling? [Was: 3 XML Design Principles]
• Previous by thread: RE: What is coupling? [Was: 3 XML Design Principles]
• Next by thread: Re: Constraints for nested elements; key and keyref
• Index(es):
  • Date
  • Thread