Thank you! I had been trying /MyRootElement/@my...@myflag=1] which
obviously was wrong.
Liz
Vadim Gritsenko wrote:
On Jul 26, 2010, at 9:04 AM, Liz Glasser wrote:
Thank you. I have it working now. What if I have two attributes on the
MyElement named MyId and MyFlag and I want to get the MyId values for all
entries where MyFlag=1? That's really what I ultimately want.
That can easily be done with XPath: /myrooteleme...@myflag = 1]/@myId
Just pass this XPath query to Xindice:
xindice xpath -c /db/my/collection -q "/myrooteleme...@myflag = 1]/@myId"
Vadim
Liz
Vadim Gritsenko wrote:
On Jul 23, 2010, at 11:43 AM, Liz Glasser wrote:
I have a ton of records in my xindice database that look like:
<MyRootElement myId="...">.....</MyRootElement>
I need the most efficient way to get a list of all values for myId. How can I
best do this?
Basically if this was a relational database and I had a table called MyRootElement, I'd
do "select myId from MyRootElement". I need a xindice equivalent.
Hey Liz,
The query you are looking for is "/MyRootElement/@myId". Using command line you
can query it like this (replace /db/my/collection with path to your collection):
xindice xpath -c /db/my/collection -q /MyRootElement/@myId
Results should look like:
<xq:result xmlns:xq="http://xml.apache.org/xindice/Query"; myId="value"
xq:col="/db/my/collection" xq:key="MyDocument1" />
...
Now, if only some % of documents in this collection contain this root
element/attribute, then you can speed that query up by build an index on the
element/attribute pair. Index will allow query engine to skip documents which
do not have that element/attribute pair. Index also helps if you want to find a
document by value of the myId attribute. Command to build the index looks like:
xindice add_indexer -c /db/my/collection -n MyRootElementMyId -p
MyRootElement@ myId
OTOH, if all documents have the same structure, then in order to extract all of
the values, query engine will have to iterate through all of the documents in
the collection - and index will be of no help.
Hope that helps.
Vadim
