- BaseX-Talk - mailman.uni-konstanz.de

Simple query
by Aaron Weber 11 Mar '17

11 Mar '17

Newbie alert. I'm trying to get my feet wet with BaseX, and in doing so, am trying to understand XQuery and how to apply it to a database full of documents (not just a single document that is typically queried). I am using Java and can post my code, but with a LocalSession, and a query, the following produces 0 results. For $doc in collection() return $doc I realize there's no "where", and in the sql world that would match all. Maybe not in XQuery? Obviously just a test query, but I need to start somewhere. :-) Thanks for any help! -- AJ

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Tail Recursion Error on startup
by buddyonweb-software＠yahoo.com 11 Mar '17

11 Mar '17

When we start up BaseX (whether the server or the GUI) and run a particular a query against a particular .xqm file, we always get a tail recursion error. Error:[bxerr:BASX0005] Stack Overflow: Try tail recursion? If we attempt to execute it again (sometimes twice, but have done so repeatedly up to 5 times), the error goes away and all is fine. Is there anything you can suggest or anything we can provide you to see how to eliminate this. This is particularly problematic on our server when we reboot our production application.Anything you can suggest or anyway we can help is much appreciated. Buddy

3 7

Angular(2) ToH with Basex backend
by Rob Stapper 11 Mar '17

11 Mar '17

Hi, So finally I got the Tour of Heroes from the Angular(2) tutorial [1] working with BaseX as database backend. Everything works pretty well except for one thing: When adding a new record, Angular expects the backend (BaseX) to create an unique ID for the record and send it, together with the original, back to the angular-frontend [2]. In BaseX however, it is not possible to retrieve updated data from within the same transaction as the update of the database took place. The work around is to fetch the updated record outside the updating-transaction by means of a web:redirect to the link that retrieves a record [3]. This work around has two major disadvantages: 1. one can never be a 100% sure that the fetched data is exactly the data as it was stored in the base because updating and fetching are two separate transactions. 2. this only works if the records have a unique set of key fields. This doesn't always have to be the case. I've reported this situation a while ago and I wouldn't come back on it if the Angular-way of working didn't come up with the same situation. In my opinion BaseX would even be better equipped as database backend as it is if it was possible to fetch the updated date in the database from within the same transaction as the update took place. Is this something that could be considered for a future release? Cheers, Rob Stapper PS. I got this far thanks to the suggestions on CORS. [1] https://angular.io/docs/ts/latest/tutorial [2] https://angular.io/docs/ts/latest/tutorial/toh-pt6.html chapter: "Add a hero". [3] declare %rest:path("/product/save") %rest:POST("{ $parameterSet}") %updating function _:product.save ( $parameterSet as array(*) ) { ( db:output( web:redirect( "/product/find" , map{ "code" : $parameterSet(2) } ) ) , dbx:save( $_:dataBase , $_:objectType , trace( $parameterSet(1), "objectID:" ) , product:new( $parameterSet(2) , $parameterSet(3) , $parameterSet(4) ) ) )

4 3

Flush command and data corruption
by Colin Delacroix 10 Mar '17

10 Mar '17

Hi everyone, (warning this is a long read) I'm using server version 8.6.1 and writing a Java client to move lots of documents from a SQL database to a BaseX database. The basic version works just fine. Tested up to 1M documents. Now I'm trying to do exactly the same but with AUTOFLUSH disabled + manually FLUSH every N documents and it fails after just a few inserts. Pseudo code: (set up client session, create and open new database) session.execute(new Set(MainOptions.AUTOFLUSH, false)); int i = 0; while(doc = nextDocs()) { session.add(doc.getKey(), doc.getInputStream()); if(i++ % 10 == 0) { /* value reduced to 10 for testing purposes */ session.execute(new Flush()); } } (tear down session) Remember tha After the first FLUSH has been issued, the ADD directive starts randomly throwing a org.basex.core.BaseXException (when using the BaseXClient implementation it was its inner ok() method that started returning false). I tracked the root cause in the server: the SAXParser complaining about the documents not being well-formed (the exact same documents are all imported fine with AUTOFLUSH on). In the server standard logs I can see why: parts of those documents are suddenly missing (usually the beginning + command part) at parse time! That is the symptom, now for the cause I'm also observing that the ADD and FLUSH directive in the logs are out of order, exactly like what would happen in the FLUSH commands were not properly queued. I was expecting something like : ADD ADD ADD (N times) FLUSH ADD ADD ADD (N times) FLUSH etc. Instead I'm observing ADD FLUSH ADD FLUSH ADD FLUSH (etc) then ADD ADD ADD (lots of them) ERROR So for now I'm keeping autoflush on :) but is there anything obvious I could try there? (server runs on linux openjdk 1.8.0_91, client runs in Tomcat on Windows Oracle JDK 1.8.0_121) Thanks, Colin

2 2

[XPTY0004] Item expected, sequence found
by Bram Vanroy 08 Mar '17

08 Mar '17

Hi BaseX peeps I'm running BaseX 8.6.1 on Windows, and I'm running into an issue I can't explain. I am using BaseX to run some benchmarks. As a benchmark I am running different XPath structures to match on the same database. In other words, in a file of a hundred lines each line is an XPath structure, and with Perl I query each line and measure the time it takes. Simple enough, right? The strange thing is that my script runs fine but it crashes on line 17, which is this XPath code: //node[@cat="pp" and node[@rel="hd" and @pt="vz" and number(@begin) < number(../node[@rel="obj1" and @cat="np"]/node[@rel="mod" and @cat="pp"]/node[@rel="hd" and @pt="vz"]/@begin)] and node[@rel="obj1" and @cat="np" and node[@rel="mod" and @cat="pp" and node[@rel="hd" and @pt="vz" and number(@begin) < number(../node[@rel="obj1" and @cat="np"]/node[@rel="mod" and @cat="pp"]/node[@rel="hd" and @pt="vz"]/@begin)] and node[@rel="obj1" and @cat="np" and node[@rel="mod" and @cat="pp" and node[@rel="hd" and @pt="vz"]]]]]] Admittedly, it's quite a long string, but I don't see anything wrong with it and I don't think the error lies in the XPath. The full trace is like follows: [XPTY0004] Item expected, sequence found: (attribute begin {"6"}, ...). at C:\xampp\htdocs\grinding\BaseXClient.pm line 213. at C:\xampp\htdocs\grinding\BaseXClient.pm line 213. Query::exc("\x{5}", 133) called at C:\xampp\htdocs\grinding\BaseXClient.pm line 177 Query::execute(Query=HASH(0x3adac40)) called at SonarBenchNew.pl line 249 main::query_sonar("for \$node in db:open(\"WRPEE0000000treebank\")/treebank//node[\@"...) called at SonarBenchNew.pl line 176 main::loop_databases(ARRAY(0x31a2ae0), "//node[\@cat=\"pp\" and node[\@rel=\"hd\" and \@pt=\"vz\" and number(\@"...) called at SonarBenchNew.pl line 140 main::regular_sonar("//node[\@cat=\"pp\" and node[\@rel=\"hd\" and \@pt=\"vz\" and number(\@"...) called at SonarBenchNew.pl line 110 I have found that the XPTY0004 error is often caused by an order-by clause in XQuery but I don't have that. The full XQuery for the XPath is as follows: for $node in db:open("WRPEE0000000treebank")/treebank//node[@cat="pp" and node[@rel="hd" and @pt="vz" and number(@begin) < number(../node[@rel="obj1" and @cat="np"]/node[@rel="mod" and @cat="pp"]/node[@rel="hd" and @pt="vz"]/@begin)] and node[@rel="obj1" and @cat="np" and node[@rel="mod" and @cat="pp" and node[@rel="hd" and @pt="vz" and number(@begin) < number(../node[@rel="obj1" and @cat="np"]/node[@rel="mod" and @cat="pp"]/node[@rel="hd" and @pt="vz"]/@begin)] and node[@rel="obj1" and @cat="np" and node[@rel="mod" and @cat="pp" and node[@rel="hd" and @pt="vz"]]]]]]let $sentid := ($node/ancestor::alpino_ds/@id)let $sentence := ($node/ancestor::alpino_ds/sentence)let $tb := \'WRPEE0000000treebank\' return <match>{data($sentid)}||{data($sentence)}||{data($tb)}</match> I don't know if you guys can give me directions solely based on this. But if you could point me to a likely cause, e.g. input OR database contents, that would be great. Thanks in advance! Bram Vanroy https://bramvanroy.be

3 7

Re: [basex-talk] starting and closing HTTP server giving errors
by kalibuk＠centrum.cz 08 Mar '17

08 Mar '17

Hi Marco, thanks for reply I tried your latest release (8.6.2.x) and it seems helped to get HTTP server stopped ok. Otherwise starting the server is still giving me the error. Automation is out of way as it may be reproduced manually in command line see: c:\>basexhttp.bat -S Connection failed (port: 8984). c:\>basexhttpstop.bat HTTP Server was stopped (port: 8984). c:\> Any idea why it hands back connection failed message while I can ping it like this while running? C:\windows\system32>netstat -anb | find "8984" TCP 0.0.0.0:8984 0.0.0.0:0 LISTENING TCP [::]:8984 [::]:0 LISTENING Thanks, Jan -------------------------------------------------------------------------------------------------------------------------------------------- Hallo, I'm trying to get strating and stopping of BaseX HTTP server automated. ? Whats wrong with starting: Once trying to run in command line "basexhttp.bat -S" I get "Connection failed (port: 8984)." But server is running (!?) and I can create socket to comunicate with. ? Whats wrong with stopping: Once trying to run in command line "basexhttpstop.bat" I get it hanged and need to terminate job or on another attempt I get back "Connection failed (port: 8985)." And I cannot communicate with server so it seems that it really got stopped. ? It's tricky to automate that if I get errors on every attempt to start/stop it. Could you advice? ? Third error what I ocasionally can get back after trying to run server is: "Error occurred during initialization of VM Could not reserve enough space for 1433600KB object heap" ? Behaviour is same for 8.6.0 and 8.6.1. I have just updated Java RT to latest. ? Regards,? Jan, Brno ? ? ?

2 1

starting and closing HTTP server giving errors
by kalibuk＠centrum.cz 07 Mar '17

07 Mar '17

Hallo, I'm trying to get strating and stopping of BaseX HTTP server automated. Whats wrong with starting: Once trying to run in command line "basexhttp.bat -S" I get "Connection failed (port: 8984)." But server is running (!?) and I can create socket to comunicate with. Whats wrong with stopping: Once trying to run in command line "basexhttpstop.bat" I get it hanged and need to terminate job or on another attempt I get back "Connection failed (port: 8985)." And I cannot communicate with server so it seems that it really got stopped. It's tricky to automate that if I get errors on every attempt to start/stop it. Could you advice? Third error what I ocasionally can get back after trying to run server is: "Error occurred during initialization of VM Could not reserve enough space for 1433600KB object heap" Behaviour is same for 8.6.0 and 8.6.1. I have just updated Java RT to latest. Regards, Jan, Brno

2 1

Java bindings
by meumapple 06 Mar '17

06 Mar '17

Hi, I have a java parser (opennlp-tools-1.7.2.jar) whose main class is "opennlp.tools.cmdline.CLI" At the command line I run it with opennlp POSTagger mymodel.bin (opennlp is a bash script running the abovementioned jar file). After that I am asked interactively for the text to parse. Is it possible to invoke the command from XQuery via java bindings? I have put the opennlp jar files in the repo folder and I have tried "import module namespace m = "java.opennlp.tools.cmdline.CLI;" but the I get the "module not found error" Thanks! Joseph

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Re: [basex-talk] HTTP status codes
by Marco Lettere 06 Mar '17

06 Mar '17

Hi Christoph, it worked for me when putting the rest_errors.xqm in the webapp folder and rewrriting your import in this way: import module namespace err="error" at "rest_errors.xqm"; > curl -v http://localhost:9984/softwareberatung/rev/2017/12 Trying 127.0.0.1... * Connected to localhost (127.0.0.1) port 9984 (#0) > GET /softwareberatung/rev/2017/12 HTTP/1.1 > Host: localhost:9984 > User-Agent: curl/7.47.0 > Accept: */* > < HTTP/1.1 404 Not Found < Set-Cookie: JSESSIONID=6ylp1ounz561183u198394hjs;Path=/ < Expires: Thu, 01 Jan 1970 00:00:00 GMT < Content-Type: text/plain;charset=UTF-8 < Content-Length: 25 < Server: Jetty(8.1.18.v20150929) < * Connection #0 to host localhost left intact Revenue 12 does not exist Working with the repo is something that I never got right but probably I should just carefully re-read the docs at [1]. Regards, Marco. [1] http://docs.basex.org/wiki/Repository On 05/03/2017 13:45, Christoph Gaukel wrote: > Hi Marco, > > thank you for your reply. It works fine, when I put the declaration > direct into my rest-module: > > module namespace page = 'rev'; > > declare > %rest:error("*:notfound") > %rest:error-param("description", "{$description}") > function page:not-found-error($description as xs:string) > { > <rest:response> > <http:response status="404"> > <http:header name="Content-type" value="text/plain"/> > </http:response> > </rest:response>, $description > }; > > declare > %rest:path("softwareberatung/rev/{$year}/{$id}") > %rest:GET > %output:method("json") > function page:get-revenue( > $year, > $id > ) { > error(xs:QName('err:notfound'), 'Revenue ' || $id || ' does not exist') > }; > > but not if I put this code into module rest_errors.xqm: > > module namespace err = "error"; > declare namespace rest = "http://exquery.org/ns/restxq"; > declare namespace http = "http://expath.org/ns/http-client"; > > declare > %rest:error("*:notfound") > %rest:error-param("description", "{$description}") > function err:not-found-error($description as xs:string) > { > <rest:response> > <http:response status="404"> > <http:header name="Content-type" value="text/plain"/> > </http:response> > </rest:response>, $description > }; > > > and import the module: > > module namespace page = 'rev'; > import module namespace err="error" > at "../repo/rest_errors.xqm"; > > declare > %rest:path("softwareberatung/rev/{$year}/{$id}") > %rest:GET > %output:method("json") > function page:get-revenue( > $year, > $id > ) { > error(xs:QName('err:notfound'), 'Revenue ' || $id || ' does not exist') > }; > > > This returns status code 400 instead of 404! > > Regards > > Christoph > > > > Am 05.03.2017 um 12:31 schrieb Marco Lettere: >> Hi Chrostoph, >> the best way I've found out to organize error responses in a RestXQ >> context is to exploit BaseX built-in error interceptors. [1] >> What we usually do is write a module with interceptors (basically >> annotated functions ) like the following: >> >> module namespace e = "urn:myerr"; >> >> declare >> %rest:error("*:notfound") >> %rest:error-param("description", "{$description}") >> function e:login-error($description as xs:string) >> { >> <rest:response> >> <http:response status="404"> >> <http:header name="Content-type" value="text/plain"/> >> </http:response> >> </rest:response>, $description >> >> }; >> >> Here we just use <rest:response> to hand-craft the response we need >> when an exception with the annotated code (*:notfound) is generated >> (and not catched before). >> In your case rewriting your throwing like the following would then be >> catched by the above interceptor. >> >> fn:error(xs:QName('err:notfound'), 'Invoice ' || $id || ' does not >> exist'). >> >> You can intercept with the proper annotations all information you >> usually have in an exception handler (line number, value, stack >> trace, ...) and this can be exploited, for example, in order to make >> the status of the response dynamic. You could pass it into the error >> interceptor with the value field for instance. >> >> Hope you can move ahead with this info. >> Regards, >> Marco. >> >> [1] http://docs.basex.org/wiki/RESTXQ#Error_Handling >> >> >> On 05/03/2017 07:33, Christoph Gaukel wrote: >>> Hi, >>> >>> i tried to return http-status 404, but my service returns status 400: >>> >>> This is the code in my XQuery: >>> >>> fn:error(xs:QName('error'), 'Invoice ' || $id || ' does not exist', >>> 404) >>> >>> >>> This is what curl prints: >>> >>> * Trying 127.0.0.1... >>> * Connected to localhost (127.0.0.1) port 8984 (#0) >>> > GET /softwareberatung/revenues/2015/15-123 HTTP/1.1 >>> > Host: localhost:8984 >>> > User-Agent: curl/7.47.0 >>> > Accept: */* >>> > >>> < HTTP/1.1 400 Bad Request >>> < Set-Cookie: JSESSIONID=cfedc7x61od51p8o40uxm8dfe;Path=/ >>> < Expires: Thu, 01 Jan 1970 00:00:00 GMT >>> < Content-Type: text/plain;charset=UTF-8 >>> < Content-Length: 97 >>> < Server: Jetty(8.1.18.v20150929) >>> < >>> Stopped at /home/christoph/basex/restxq/Revenue.xqm, 64/19: >>> * Connection #0 to host localhost left intact >>> [error] Invoice 15-123 does not exist >>> >>> >>> Regards >>> >>> Christoph Gaukel >>> >>> >> >> >

1 0

preserve auth behavior like older basex versions
by Erik Peterson 05 Mar '17

05 Mar '17

For RESTXQ auth its unclear to me what the entry is to preserve older versions of basex auth. Thank! see... http://docs.basex.org/wiki/Web_Application - Authentication was readded to RESTXQ. As a consequence, you need to specify the admin user in your web.xml file if you want to preserve the behavior of older versions of BaseX. - In turn, if users are defined in the web.xml file, no passwords must be specified anymore. - The server-side authentication method, and default users, are now enforced and cannot be overwritten by client.

2 1