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

Question for XQJ to update
by Qu Xia 08 Apr '10

08 Apr '10

I made a simple XML called order.xml like this: -------------order.xml-------------- <orders> <order> <name>cola</name> <price>3.0</price> <factory>Number 1</factory> </order> <order> <name>coffee</name> <price>5.0</price> <factory>Number 2</factory> </order> </orders> -------------------------------------------- Now I want to update the price of the coffee to 6.0 with XQJ, so I got the following code: String driverName = "org.basex.api.xqj.BXQDataSource"; Class<?> driverClass = Class.forName(driverName); XQDataSource dataSource = (XQDataSource)driverClass.newInstance(); XQConnection xqc = dataSource.getConnection(); String updateString = "declare variable $node := doc('etc/xml/orders.xml')//order[name='coffee']; "+ "replace value of node $node/price with '5.0', " + "return " + "put(doc('etc/xml/orders.xml'), 'orders.xml')"; XQExpression xqu = xqc.createExpression(); xqu.executeQuery(updateString); xqu.close(); unfortunately, it throws an exception. I tried many different ways and fails all the time. could any tell me the right "updateString"? thanks a lot. -- Xia Qu Technology Center of Software Engineering, Institute of Software, Chinese Academy of Sciences Beijing, 100190, China Email (work):quxia08@otcaix.iscas.ac.cn Email (personal): tsuxia(a)gmail.com Mobile:(86) 1300-1010-069

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How can I connected to the server usering XQJ
by 屈夏 07 Apr '10

07 Apr '10

Hi, I am a freshman here using BaseX6. I want to use XQJ API to connect with the BaseX Server, I tried many kinds of properties, but it does not work, did anyone try it before? thanks a lot.. -- Xia Qu Technology Center of Software Engineering, Institute of Software, Chinese Academy of Sciences Beijing, 100190, China Email (work):quxia08@otcaix.iscas.ac.cn Email (personal): tsuxia(a)gmail.com Mobile:(86) 1300-1010-069

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basex xquery optimization not using attribute index on "joins"?
by Sandra Maria Silcot 07 Apr '10

07 Apr '10

Hi all, First, thanks to the developers for a great piece of software. I am having difficulty getting an xquery on a large database to run using indexed attributes when a "join" idiom is used. I have a large basex database, with multiple documents. One of those contains <rs> elements as shown below, where the @corresp attribute contains values which are identical to the @key attribute on <person> elements, which live in multiple separate files: <personGrp type="match:policeNum+ship" size="3"><persName> <rs corresp="c23a2866">Corper, Jno (Pn:1000C)...</rs> <rs corresp="dlm18192024">Corper, John (Pn:1000C)...</rs> <rs corresp="c31a31061000" >Corper, Jno (Pn:1000CC)...</rs> </persName></personGrp> I know indexes have been built as xpaths like this are lightening quick: //person[@key="c23a2866"] or //rs[@corresp="dlm18192024"] But when I do this, it is glacial (nearly 1 minute): EG(A) for $rs in //rs[@corresp="c31a31061000"]/../..//rs let $keyval := data($rs/@corresp) return //person[@key=$keyval] I am using BaseX6.jar on XP. When I look at the query plan, the ONLY time the attribute index used is on the //rs[@corresp="c31a31061000"] part. I can get it to run fast and return the 3 matched <person> elements using the attribute index using basex:eval, like this: EG(B) for $rs in data(//rs[@corresp="c31a31061000"]/../..//rs/@corresp) let $s := concat("//person[@key='",$rs,"']") return basex:eval($s) So rather than execute this query asa "join" -- a manner which seem widespread in the xquery world -- I must manually build and execute each //person[@key='string'] request "manually" to get basex to use its attribute index. Whilst this works, it seems a rather strange idiom to have to employ, and locks my queries into basex. Is the behaviour of EG(A) by design, or is it a bug that the query optimizer is failing to recognise it can use the attribute index on the //person[@key=$keyval] part? Any guidance much appreciated. Best wishes to all, Sandra.

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xqconnection issue
by Travis Webb 05 Apr '10

05 Apr '10

I am having a strange issue using the XQJ libary. Anytime I make a change to the database (inserting / updating a node), subsequent queries perform as if that change was never made. However, if I create a new XQConnection to the database, those changes are reflected. So every time I update the database, I'm having to establish a new connection in order to see my changes. Is this expected behavior? If not, any ideas why this is happening? Thanks -tjw

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Bug: baseX can't create XMLDB with non utf-8 xml String
by l0979365428＠gmail.com 05 Apr '10

05 Apr '10

Dear baseX creater: If it is xml file ,it 's ok. If it is xml String, BaseX only receives utf-8 encoding of XML. The reasion is : //---------------------------------------------------// public static IO get(final String s) { if(s == null) return new IOFile(""); if(s.startsWith("<")) return newIOContent(Token.token(s)); if(s.startsWith("http://")) return new IOUrl(s); return new IOFile(s); //---------------------------------------------------------// public static byte[] token(final String s) { final int l = s.length(); if(l == 0) return EMPTY; final byte[] bytes = new byte[l]; for(int i = 0; i < l; i++) { final char c = s.charAt(i); if(c > 0x7F) return utf8(s); bytes[i] = (byte) c; } return bytes; //-----------------------------------------------// Doesn't parse with the head of XML file. But this programe create xml struts with Sax which pares the xml with the head info. For this reason，it'll make mistakes once the XML String is not UTF-8. I fix it : if(s.startsWith("<")) return new IOContent(Token.encoding(s)); //----------------------------------------------// public static byte[] encoding(final String s) { final int l = s.length(); if(l == 0) return EMPTY; int i=0; int j =0; StringBuilder ss=new StringBuilder(); char hope[]=new char[]{'c','=','"','"'}; while (true) { final char c = s.charAt(i); if(hope[j]==c) j++; if(j==4) break; if(j>2&&c!=hope[j-1]) { ss.append(c); } i++; } final byte[] bytes = new byte[l]; for(int k = 0; k < l; k++) { final char c = s.charAt(k); if(c > 0x7F) return others(s,ss.toString()); bytes[k] = (byte) c; } return bytes; } //-----------------------------------------------// I wonder if you could fix this bug in the next version. Also BaseX doesn't support the String of xml with namespace build DB. And I have no idea. PS: BaseX57,Jdk1.5 best wishes Ruby

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.basex config file
by Travis Webb 04 Apr '10

04 Apr '10

I have another question regarding the .basex config file. How does basex determine the home directory of the current user? by looking at $HOME? I'd like to trick basex into thinking this file is somewhere else, because the hard restriction that this file must reside in the home directory of the current user will not work for our use. -tjw

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question: how to connect with base
by yasmeenzabash＠yahoo.com 02 Apr '10

02 Apr '10

Dear Sirs: My name is yasmin and I have a question about how to connect to Basex vis VS2008. I' a student in the Web Sience master and it is a small project for us to deploy one of the natinve XML DB. in a website. so it is quite confusing for me to deal with such DB. it would be agreat help from you to guide me through the steps to find how I can see and connect to BaseX via Visual Stusio 2008. and kindly would you answer my request as soon as possible. best regards. Yasmin Zabash

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Namespace conflict problem
by Jiří Kadlec 01 Apr '10

01 Apr '10

Hi all, Could you help with following error [XUDY0024] New namespaces conflict with each other. I create database in basex GUI from following XML file: <root xmlns:my="http://www.somedomain.com"> <subroot my:index="1">aaa</subroot> <subroot my:index="2">bbb</subroot> <subroot my:index="3" my:delete="true">ccc</subroot> </root> Then I try to execute following statement declare namespace my="http://www.somedomain.com"; insert node attribute my:addedAttribute {"1"} into /root/subroot[@my:index=1] Am i doing something wrong, how should i write a query which will add add my:addedAttribute {"1"} into subroot element with my:index="1". Any help appreciated Jiri

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Bug: baseX can't create XMLDB with non utf-8 xml String
by l0979365428＠gmail.com 31 Mar '10

31 Mar '10

Dear baseX creater: If it is xml file ,it 's ok. If it is xml String, BaseX only receives utf-8 encoding of XML. The reasion is : //---------------------------------------------------// public static IO get(final String s) { if(s == null) return new IOFile(""); if(s.startsWith("<")) return newIOContent(Token.token(s)); if(s.startsWith("http://")) return new IOUrl(s); return new IOFile(s); //---------------------------------------------------------// public static byte[] token(final String s) { final int l = s.length(); if(l == 0) return EMPTY; final byte[] bytes = new byte[l]; for(int i = 0; i < l; i++) { final char c = s.charAt(i); if(c > 0x7F) return utf8(s); bytes[i] = (byte) c; } return bytes; //-----------------------------------------------// Doesn't parse with the head of XML file. But this programe create xml struts with Sax which pares the xml with the head info. For this reason，it'll make mistakes once the XML String is not UTF-8. I fix it : if(s.startsWith("<")) return new IOContent(Token.encoding(s)); //----------------------------------------------// public static byte[] encoding(final String s) { final int l = s.length(); if(l == 0) return EMPTY; int i=0; int j =0; StringBuilder ss=new StringBuilder(); char hope[]=new char[]{'c','=','"','"'}; while (true) { final char c = s.charAt(i); if(hope[j]==c) j++; if(j==4) break; if(j>2&&c!=hope[j-1]) { ss.append(c); } i++; } final byte[] bytes = new byte[l]; for(int k = 0; k < l; k++) { final char c = s.charAt(k); if(c > 0x7F) return others(s,ss.toString()); bytes[k] = (byte) c; } return bytes; } //-----------------------------------------------// I wonder if you could fix this bug in the next version. Also BaseX doesn't support the String of xml with namespace build DB. And I have no idea. PS: BaseX57,Jdk1.5 best wishes Ruby

1 0

Bug: baseX can't create XMLDB with non utf-8 xml String
by l0979365428＠gmail.com 31 Mar '10

31 Mar '10

Dear baseX creater: If it is xml file ,it 's ok. If it is xml String, BaseX only receives utf-8 encoding of XML. The reasion is : //---------------------------------------------------// public static IO get(final String s) { if(s == null) return new IOFile(""); if(s.startsWith("<")) return newIOContent(Token.token(s)); if(s.startsWith("http://")) return new IOUrl(s); return new IOFile(s); //---------------------------------------------------------// public static byte[] token(final String s) { final int l = s.length(); if(l == 0) return EMPTY; final byte[] bytes = new byte[l]; for(int i = 0; i < l; i++) { final char c = s.charAt(i); if(c > 0x7F) return utf8(s); bytes[i] = (byte) c; } return bytes; //-----------------------------------------------// Doesn't parse with the head of XML file. But this programe create xml struts with Sax which pares the xml with the head info. For this reason，it'll make mistakes once the XML String is not UTF-8. I fix it : if(s.startsWith("<")) return new IOContent(Token.encoding(s)); //----------------------------------------------// public static byte[] encoding(final String s) { final int l = s.length(); if(l == 0) return EMPTY; int i=0; int j =0; StringBuilder ss=new StringBuilder(); char hope[]=new char[]{'c','=','"','"'}; while (true) { final char c = s.charAt(i); if(hope[j]==c) j++; if(j==4) break; if(j>2&&c!=hope[j-1]) { ss.append(c); } i++; } final byte[] bytes = new byte[l]; for(int k = 0; k < l; k++) { final char c = s.charAt(k); if(c > 0x7F) return others(s,ss.toString()); bytes[k] = (byte) c; } return bytes; } //-----------------------------------------------// I wonder if you could fix this bug in the next version. Also BaseX doesn't support the String of xml with namespace build DB. And I have no idea. PS: BaseX57,Jdk1.5 best wishes Ruby

1 0