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Posted to users@jackrabbit.apache.org by Zhenhua Guo <je...@gmail.com> on 2009/12/18 00:22:23 UTC
Question about query support in Jackrabbit 2.0
I read JCR2.0 spec and two query languages are supported: SQL2 and QOM.
I am using jcr2spi + spi2jcr. It looks weird considering that I can
directly use jackrabbit core. The reason is it's easy for future
extension. We can easily replace spi2jcr with spi2dav, spi2davex, etc
without modifying out code.
I constructed a query using QOM. It compiled OK, but when I ran it,
following error appeared
--------------------------
javax.jcr.query.InvalidQueryException: Query:
SELECT gadget1.* FROM [gr:textblob] AS tagtb INNER JOIN [gr:gadgettag]
AS tag INNER(*)JOIN [gr:gadgettags] AS tags INNER JOIN
[gr:gadgetinrepo] AS gadget1 ON ISCHILDNODE(tags, gadget1) ON
ISCHILDNODE(tag, tags) ON ISCHILDNODE(tagtb, tag) INNER JOIN
[gr:textblob] AS catkindtb INNER JOIN [gr:categorykind] AS
categorykind INNER JOIN [gr:gadgetcategory] AS category INNER JOIN
[gr:gadgetcategories] AS categories INNER JOIN [gr:gadgetinrepo] AS
gadget2 ON ISCHILDNODE(categories, gadget2) ON ISCHILDNODE(category,
categories) ON ISCHILDNODE(categorykind, category) ON
ISCHILDNODE(catkindtb, categorykind) ON ISSAMENODE(gadget1, gadget2,
[.]); expected: ON
org.apache.jackrabbit.commons.query.sql2.Parser.getSyntaxError(Parser.java:968)
org.apache.jackrabbit.commons.query.sql2.Parser.read(Parser.java:641)
org.apache.jackrabbit.commons.query.sql2.Parser.parseSource(Parser.java:186)
org.apache.jackrabbit.commons.query.sql2.Parser.createQueryObjectModel(Parser.java:112)
org.apache.jackrabbit.commons.query.sql2.SQL2QOMBuilder.createQueryObjectModel(SQL2QOMBuilder.java:55)
org.apache.jackrabbit.core.query.QOMQueryFactory.createQuery(QOMQueryFactory.java:69)
org.apache.jackrabbit.core.query.CompoundQueryFactory.createQuery(CompoundQueryFactory.java:67)
org.apache.jackrabbit.core.query.QueryManagerImpl.createQuery(QueryManagerImpl.java:98)
org.apache.jackrabbit.spi2jcr.RepositoryServiceImpl.createQuery(RepositoryServiceImpl.java:1762)
org.apache.jackrabbit.spi2jcr.RepositoryServiceImpl.checkQueryStatement(RepositoryServiceImpl.java:1063)
org.apache.jackrabbit.jcr2spi.WorkspaceManager.checkQueryStatement(WorkspaceManager.java:320)
org.apache.jackrabbit.jcr2spi.query.QueryImpl.<init>(QueryImpl.java:140)
org.apache.jackrabbit.jcr2spi.query.QueryObjectModelImpl.<init>(QueryObjectModelImpl.java:62)
org.apache.jackrabbit.jcr2spi.query.QueryManagerImpl$QOMFactory.createQuery(QueryManagerImpl.java:167)
org.apache.jackrabbit.spi.commons.query.qom.QueryObjectModelFactoryImpl.createQuery(QueryObjectModelFactoryImpl.java:173)
--------------------------
I formatted the generated sql2 statement in a readable way:
--------------------------
SELECT gadget1.*
FROM
[gr:textblob] AS tagtb INNER JOIN
[gr:gadgettag] AS tag INNER JOIN
[gr:gadgettags] AS tags INNER JOIN
[gr:gadgetinrepo] AS gadget1
ON ISCHILDNODE(tags, gadget1)
ON ISCHILDNODE(tag, tags)
ON ISCHILDNODE(tagtb, tag)
INNER JOIN
[gr:textblob] AS catkindtb INNER JOIN
[gr:categorykind] AS categorykind INNER JOIN
[gr:gadgetcategory] AS category INNER JOIN
[gr:gadgetcategories] AS categories INNER JOIN
[gr:gadgetinrepo] AS gadget2
ON ISCHILDNODE(categories, gadget2)
ON ISCHILDNODE(category, categories)
ON ISCHILDNODE(categorykind, category)
ON ISCHILDNODE(catkindtb, categorykind)
ON ISSAMENODE(gadget1, gadget2, [.]);
--------------------------
The query includes netsted joins (A operand of a join is another
join). Maybe that is not supported by spi2jcr now?
Thanks
Gerald
Re: Question about query support in Jackrabbit 2.0
Posted by Zhenhua Guo <je...@gmail.com>.
I am using Jackrabbit 2.0 Beta3.
I will create a Jira issue soon.
Gerald
On Tue, Dec 22, 2009 at 5:51 AM, Thomas Müller <th...@day.com> wrote:
> Hi,
>
> This looks like a bug in Jackrabbit. Could you create a Jira issue?
> What version or Jackrabbit do you use?
>
> Regards,
> Thomas
>
Re: Question about query support in Jackrabbit 2.0
Posted by Thomas Müller <th...@day.com>.
Hi,
This looks like a bug in Jackrabbit. Could you create a Jira issue?
What version or Jackrabbit do you use?
Regards,
Thomas
Re: Question about query support in Jackrabbit 2.0
Posted by Zhenhua Guo <je...@gmail.com>.
Thanks. I rewrote the query according to your suggestion and replaced
INNER JOIN with OUTER JOIN because some selectors generate empty node
sets.
For a sample query like this:
---------------------------
SELECT categories.*
FROM [categories] AS categories LEFT OUTER JOIN
[category] AS category
ON ISCHILDNODE(category, categories)
---------------------------
If selector "category" generates empty node set, is that OK? It seems
that I always got following exception:
java.lang.NullPointerException
at org.apache.jackrabbit.core.query.lucene.join.ParentNodeJoin.getMatchingScoreNodes(ParentNodeJoin.java:75)
at org.apache.jackrabbit.core.query.lucene.join.Join.nextScoreNodes(Join.java:265)
at org.apache.jackrabbit.core.query.lucene.join.Join.nextScoreNodes(Join.java:261)
at org.apache.jackrabbit.core.query.lucene.FilterMultiColumnQueryHits.nextScoreNodes(FilterMultiColumnQueryHits.java:63)
at org.apache.jackrabbit.core.query.lucene.QueryResultImpl.collectScoreNodes(QueryResultImpl.java:347)
at org.apache.jackrabbit.core.query.lucene.QueryResultImpl.getResults(QueryResultImpl.java:310)
at org.apache.jackrabbit.core.query.lucene.MultiColumnQueryResult.<init>(MultiColumnQueryResult.java:62)
at org.apache.jackrabbit.core.query.lucene.QueryObjectModelImpl.execute(QueryObjectModelImpl.java:137)
at org.apache.jackrabbit.core.query.QueryImpl.execute(QueryImpl.java:127)
Thanks
Gerald
On Fri, Dec 18, 2009 at 7:09 AM, Thomas Müller <th...@day.com> wrote:
> Hi,
>
> The ON needs to follow the INNER JOIN clause, like this.
>
> SELECT ... FROM ...
> INNER JOIN ... ON ...
> INNER JOIN ... ON ...
> INNER JOIN ... ON ...
> INNER JOIN ... ON ...
>
> Regards,
> Thomas
>
Re: Question about query support in Jackrabbit 2.0
Posted by Thomas Müller <th...@day.com>.
Hi,
The ON needs to follow the INNER JOIN clause, like this.
SELECT ... FROM ...
INNER JOIN ... ON ...
INNER JOIN ... ON ...
INNER JOIN ... ON ...
INNER JOIN ... ON ...
Regards,
Thomas