Informix IDS 12.25 is returning NULL whenever an #attribute is specified. In the image below we have the same document being queried by two statements. The difference between the statements is that one of them specifies an #attribute. While the other doesn't. And, as is possible to see in the image, the attribute indeed exists, because it's returned by one of the columns.
I've been searching a lot, seeing documentations and documentations, all places are saying that the syntax is correct. I don't know what to do anymore. Really thanks.
[Edit]
Here goes a sample of the xml File I'm working with:
<Frame>
<Shape sizeX="5400" sizeY="4400" distance="1800">
<ShapePoint>
<Point direction="0" radius="266" />
<Point direction="144" radius="280" />
<Point direction="243" radius="289" />
<Point direction="279" radius="291" />
</ShapePoint>
</Shape>
</Frame>
Alternative approaches for this problem, if mainly using the database engine, also would be extremely welcomed.
It's definitely a valid Xpath, except the first one selects a node, and the one that isn't working selects a string, which makes me think extractclob() is having a problem with this type of result.
Here's my test in Python to demonstrate this is the correct xpath for the given xml.
In [16]: tree.xpath('/Frame/Shape/ShapePoint/Point[1]')
Out[16]: [<Element Point at 0x102d68bc0>]
In [17]: tree.xpath('/Frame/Shape/ShapePoint/Point[1]/#radius')
Out[17]: ['266']
What happens if you use extractvalueclob() instead?
https://www.ibm.com/support/knowledgecenter/SSGU8G_12.1.0/com.ibm.xml.doc/ids_xpextractvalue.htm
Related
I'm working with SQL data hosted by a 3rd party, and am trying to pull some specific information for reporting. However, some of what I need to parse out is in XML format, and I'm getting stuck. I'm looking for the syntax to pull the text= values only from the XML code.
I believe the code should something like this, but most of the examples I can find online involve simpler XML hierarchy's than what I'm dealing with.
<[columnnameXML].value('(/RelatedValueListBO/Items/RelatedValueListBOItem/text())[1]','varchar(max)')>
Fails to pull any results. I've tried declaring the spacenames as well, but again...I only ever end up with NULL values pulled.
Example XML I'm dealing with:
<RelatedValueListBO xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://tempuri.org/RelatedValueListBOSchema.xsd">
<Items>
<RelatedValueListBOItem groupKey="Response1" text="Response1" selected="true" />
<RelatedValueListBOItem groupKey="Response2" text="Response2" selected="true" />
<RelatedValueListBOItem groupKey="Response3" text="Response3" selected="true" />
</Items>
</RelatedValueListBO>
Ideally I'd like to pull response1; response2; response3 into a single column. Allowing for the fact that multiple responses may exist. I believe I'm getting stuck with the basic code I've been trying due to the namespaces associated to RelatedValueListBO and the fact that what I want is grouped in groupKey, text, and selected, instead of the value I want just being under the Items node.
You have the namespaces defined in your XML, so you need to define them in the XQuery too.
Fast and dirty method is to replace all namespaces with a "*":
SELECT #x.value('(/*:RelatedValueListBO/*:Items/*:RelatedValueListBOItem/#text)[1]','varchar(max)')
To get all responses in a single column you can use:
SELECT
Item.Col.value('./#text','varchar(max)') X
FROM #x.nodes('/*:RelatedValueListBO/*:Items/*:RelatedValueListBOItem') AS Item(Col)
If you need a better performance, you may need to define namespaces properly.
You can use something like this to extract the value of "text" in the first node of RelatedValueListBOItem
SELECT extractvalue(value(rs), '//RelatedValueListBOItem[1]/#text')
FROM TABLE (xmlsequence(extract(sys.xmltype('<RelatedValueListBO>
<Items>
<RelatedValueListBOItem groupKey="Response1" text="Response1"
selected="true" />
<RelatedValueListBOItem groupKey="Response2" text="Response2"
selected="true" />
<RelatedValueListBOItem groupKey="Response3" text="Response3"
selected="true" />
</Items>
</RelatedValueListBO>'),'/RelatedValueListBO/Items'))) rs;
Hi I am new to XML manipulation, my question would be if there is a possibility of detecting if the XML node is an empty node like this: <gen:nodeName />
I am able to manipulate single nodes however I would be interested if there is an approach like a loop or recursive function that could save some time doing manual labor looking trough every single node. I have no idea how to approach this problem though.
Thanks for help.
You did not specify the dialect of SQL ([sql] is not enough, please specify always the RDBMS incl. version).
This is for SQL-Server, but the semantics should be the same.
DECLARE #xml XML=
N'<root>
<SelfClosing />
<NoContent></NoContent>
<BlankContent> </BlankContent>
<HasContent>blah</HasContent>
<HasContent>other</HasContent>
</root>';
SELECT #xml.query(N'/root/*') AS AnyBelowRoor --All elements
,#xml.query(N'/root/*[text()]') AS AnyWithTextNode --blah and other
,#xml.query(N'/root/*[not(text())]') AS NoText --no text
,#xml.query(N'/root/*[text()="blah"]') AS AnyWithTextNode--blah only
The <SelfClosing /> is semantically the same as the <NoContent><NoContent>. There is no difference.
It might be a surprise, but a blank as content is taken as empty too.
So the check for empty or not empty is the check for the existance of a text() node. one can negate this with not() to find all without a text().
Interesting: The result for NoText comes back as this (SQL-Server)
<SelfClosing />
<NoContent />
<BlankContent />
The three elements are implicitly returned in the shortest format.
I am using an API call similar to http://en.wikipedia.org/w/api.php?action=query&list=geosearch&gsradius=10000&gscoord=41.426140|26.099319.
I returns something like this
<?xml version="1.0"?>
<api>
<query>
<geosearch>
<gs pageid="27460829" ns="0" title="Kostilkovo" lat="41.416666666667" lon="26.05" dist="4245.1" primary="" />
<gs pageid="27460781" ns="0" title="Belopolyane" lat="41.45" lon="26.15" dist="4988.7" primary="" />
<gs pageid="27460862" ns="0" title="Siv Kladenets" lat="41.416666666667" lon="26.166666666667" dist="5713.5" primary="" />
<gs pageid="13811116" ns="0" title="Svirachi" lat="41.483333333333" lon="26.116666666667" dist="6521.9" primary="" />
<gs pageid="27460810" ns="0" title="Gorno Lukovo" lat="41.366666666667" lon="26.1" dist="6613.4" primary="" />
<gs pageid="27460799" ns="0" title="Dolno Lukovo" lat="41.366666666667" lon="26.083333333333" dist="6746.2" primary="" />
<gs pageid="27460827" ns="0" title="Kondovo" lat="41.433333333333" lon="26.016666666667" dist="6937" primary="" />
<gs pageid="27460848" ns="0" title="Plevun" lat="41.45" lon="26.016666666667" dist="7383.1" primary="" />
<gs pageid="24179704" ns="0" title="Villa Armira" lat="41.499069444444" lon="26.106263888889" dist="8130" primary="" />
<gs pageid="27460871" ns="0" title="Zhelezari" lat="41.413333333333" lon="25.998333333333" dist="8540.1" primary="" />
</geosearch>
</query>
</api>
But while I am actually trying to get some pictures of those pages, subsequent calls are needed, like
to get some page images
http://en.wikipedia.org/w/api.php?action=query&prop=images&pageids=13843906
then, to get image info
http://en.wikipedia.org/w/api.php?action=query&titles=File:Alexandru_Ioan_Cuza_Dealul_Patriarhiei.jpg&prop=imageinfo&iiprop=url
Well, even if this gets me what I ultimately need, it is not efficient at all.
I would like to know if there are some parameters for this calls, or maybe completely other call(s) that would bring all this info in maximum 2 steps/calls. It would be great, though, if it would be only one.
Wow, I had no idea that such a feature exists nowadays! But to answer your question, since it's a list query, you can probably use it as a generator.
Let's try it:
Original geosearch query: http://en.wikipedia.org/w/api.php?action=query&list=geosearch&gsradius=10000&gscoord=41.426140|26.099319
Generator query to get images on matching pages: http://en.wikipedia.org/w/api.php?action=query&prop=images&imlimit=max&generator=geosearch&ggsradius=10000&ggscoord=41.426140|26.099319
The prop=images query can also be used as a generator, so you can also do this:
Get URLs for all images on a list of pages: http://en.wikipedia.org/w/api.php?action=query&prop=imageinfo&iiprop=url&generator=images&gimlimit=max&pageids=13811116|24179704|27460781|27460799|27460810|27460827|27460829|27460848|27460862|27460871
Alas, AFAIK you can't nest generators, so you can't do both steps in one query. You can either:
get the list of images in one query, and then use another query to get the URLs, or
start with the basic geosearch query to get the page IDs, and then get the images and their URLs in another query.
Alas, it turns out that both of these options fail to give you some information that you may want. If you use list=geosearch as a generator, you don't get the coordinate information that you may need if you e.g. wish to display the results on a map. On the other hand, using prop=images as a generator makes you miss out on something even more important: the knowledge of which images are used on which pages!
Thus, unfortunately, it seems that, if your goal is to place images on a map, you'll probably have to do it with three separate queries. At least you can still query multiple pages / images in one request, so you shouldn't need more than three (until you hit the query limits and need to use continuations, that is).
(Also, doing it in three steps lets you apply some filtering to the images before the third step. For example, most of the pages returned by your example query only have the same three images — Flag of Bulgaria.svg, Ivaylovgrad Reservoir.jpg and Oblast Khaskovo.png — all of which are used via templates, and none of which really look like good choices to represent the specific location.)
Ps. If you're just interested in finding images near a particular location, even if they're not used on any specific Wikipedia article, you might want to try using geosearch directly on Wikimedia Commons. It doesn't seem to return any results for your Bulgarian example coordinates, but it works just fine in a more crowded location.
Here is an alternative to build on the previous answer. If you start with this query as a partial answer:
https://en.wikipedia.org/w/api.php?action=query&prop=images&imlimit=max&generator=geosearch&ggsradius=10000&ggscoord=41.426140|26.099319
Then you can build on this to get the information in a single query. The pageimages property can work with the generator. You cannot nest generators but you can chain properties. A query can use pageimages to get the page's main image url for each of the geosearch results. It looks like this:
https://en.wikipedia.org/w/api.php?action=query&prop=images|pageimages&pilimit=max&piprop=thumbnail&iwurl=&imlimit=max&generator=geosearch&ggsradius=10000&ggscoord=41.426140|26.099319
This query returns the image "File" names (images property) and a single URL for the main image (pageimages property). The main image of the page is all I need. You might be able to extrapolate the "file" urls by matching the changes from the file to the url that is output with the query but I cannot recommend such a hack.
The images property has a setting that is supposed to return urls for interwiki links, iwurl. I see the "file" as an interwiki link. This parameter is not working and images does not return a url. Playing on the sandbox might lead you to a better answer.
Intuitively it seems like you should be able to chain the images and imageinfo properties together. Doing so does not give the expected results.
If a single url for the main image of the page is not enough I can encourage you to play in the API sandbox to try and get what you need with some combination of properties. I am using the geosearch generator and get the page image, text description, and lat/long coordinates so that I can get the address. Good luck!
I have an application which creates datarequests which can be quite complex. These need to be stored in the database as tables. An outline of a datarequest (as XML) would be...
<datarequest>
<datatask view="vw_ContractData" db="reporting" index="1">
<datefilter modifier="w0">
<filter index="1" datatype="d" column="Contract Date" param1="2009-10-19 12:00:00" param2="2012-09-27 12:00:00" daterange="" operation="Between" />
</datefilter>
<filters>
<alternation index="1">
<filter index="1" datatype="t" column="Department" param1="Stock" param2="" operation="Equals" />
</alternation>
<alternation index="2">
<filter index="1" datatype="t" column="Department" param1="HR" param2="" operation="Equals" />
</alternation>
</filters>
<series column="Turnaround" aggregate="avg" split="0" splitfield="" index="1">
<filters />
</series>
<series column="Requested 3" aggregate="avg" split="0" splitfield="" index="2">
<filters>
<alternation index="1">
<filter index="1" datatype="t" column="Worker" param1="Malcom" param2="" operation="Equals" />
</alternation>
</filters>
</series>
<series column="Requested 2" aggregate="avg" split="0" splitfield="" index="3">
<filters />
</series>
<series column="Reqested" aggregate="avg" split="0" splitfield="" index="4">
<filters />
</series>
</datatask>
</datarequest>
This encodes a datarequest comprising a daterange, main filters, series and series filters. Basically any element which has the index attribute can occur multiple times within its parent element - the exception to this being the filter within datefilter.
But the structure of this is kind of academic, the problem is more fundamental:
When a request comes through, XML like this is sent to SQLServer as a parameter to a stored proc. This XML is shredded into a de-normalised table and then written iteratively to normalised tables such as tblDataRequest (DataRequestID PK), tblDataTask, tblFilter, tblSeries. This is fine.
The problem occurs when I want to match a given XML defintion with one already held in the DB. I currently do this by...
Shredding the XML into a de-normalised table
Using a CTE to pull all the existing data in the database into that same de-normalised form
Matching using a huge WHERE condition (34 lines long)
..This will return me any DataRequestID which exactly matches the XML given. I fear that this method will end up being painfully slow - partly because I don't believe the CTE will do any clever filtering, it will pull all the data every single time before applying the huge WHERE.
I have thought there must be better solutions to this eg
When storing a datarequest, also store a hash of the datarequest somehow and simply match on that. In the case of collision, use the current method. I wanted however to do this using set-logic. And also, I'm concerned about irrelevant small differences in the XML changing the hash - spurious spaces etc.
Somehow perform the matching iteratively from the bottom up. Eg produce a list of filters which match on the lowest level. Use this as part of an IN to match Series. Use this as part of an IN to match DataTasks etc etc. The trouble is, I start to black-out when I think about this for too long.
Basically - Has anyone ever encountered this kind of problem before (they must have). And what would be the recommended route for tackling it? example (pseudo)code would be great :)
To get rid of the possibility of minor variances, I'd run the request through an XML transform (XSLT).
Alternatively, since you've already got the code to parse this out into a denormalized staging table that's fine too. I would then simply using FOR XML to create a new XML doc.
Your goal here is to create a standardized XML document that respects ordering where appropriate and removes inconsistencies where it is not.
Once that is done, store this in a new table. Now you can run a direct comparison of the "standardized" request XML against existing data.
To do the actual comparison, you can use a hash, store the XML as a string and do a direct string comparison, or do a full XML comparison like this: http://beyondrelational.com/modules/2/blogs/28/posts/10317/xquery-lab-36-writing-a-tsql-function-to-compare-two-xml-values-part-2.aspx
My preference, as long as the XML is never over 8000bytes, would be to create a unique string (either VARCHAR(8000) or NVARCHAR(4000) if you have special character support) and create a unique index on the column.
I'm doing a research project for the summer and I've got to use get some data from Wikipedia, store it and then do some analysis on it. I'm using the Wikipedia API to gather the data and I've got that down pretty well.
What my questions is in regards to the links-alllinks option in the API doc here
After reading the description, both there and in the API itself (it's down and bit and I can't link directly to the section), I think I understand what it's supposed to return. However when I ran a query it gave me back something I didn't expect.
Here's the query I ran:
http://en.wikipedia.org/w/api.php?action=query&prop=revisions&titles=google&rvprop=ids|timestamp|user|comment|content&rvlimit=1&list=alllinks&alunique&allimit=40&format=xml
Which in essence says: Get the last revision of the Google page, include the id, timestamp, user, comment and content of each revision, and return it in XML format.
The allinks (I thought) should give me back a list of wikipedia pages which point to the google page (In this case the first 40 unique ones).
I'm not sure what the policy is on swears, but this is the result I got back exactly:
<?xml version="1.0"?>
<api>
<query><normalized>
<n from="google" to="Google" />
</normalized>
<pages>
<page pageid="1092923" ns="0" title="Google">
<revisions>
<rev revid="366826294" parentid="366673948" user="Citation bot" timestamp="2010-06-08T17:18:31Z" comment="Citations: [161]Tweaked: url. [[User:Mono|Mono]]" xml:space="preserve">
<!-- The page content, I've replaced this cos its not of interest -->
</rev>
</revisions>
</page>
</pages>
<alllinks>
<!-- offensive content removed -->
</alllinks>
</query>
<query-continue>
<revisions rvstartid="366673948" />
<alllinks alfrom="!2009" />
</query-continue>
</api>
The <alllinks> part, its just a load of random gobbledy-gook and offensive comments. No nearly what I thought I'd get. I've done a fair bit of searching but I can't seem to find a direct answer to my question.
What should the list=alllinks option return?
Why am I getting this crap in there?
You don't want a list; a list is something that iterates over all pages. In your case you simply "enumerate all links that point to a given namespace".
You want a property associated with the Google page, so you need prop=links instead of the alllinks crap.
So your query becomes:
http://en.wikipedia.org/w/api.php?action=query&prop=revisions|links&titles=google&rvprop=ids|timestamp|user|comment|content&rvlimit=1&format=xml