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RH Bugzilla Integration commented on ISPN-5561:
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Dave Stahl <dstahl(a)redhat.com> changed the Status of [bug
Problem in dealing with the HQL queries that contain string
comparison operations, when it involves empty string as an operand
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Key: ISPN-5561
URL:
https://issues.jboss.org/browse/ISPN-5561
Project: Infinispan
Issue Type: Bug
Components: Embedded Querying, Remote Querying
Affects Versions: 7.2.0.Final
Environment: Infinispan version: Infinispan 7.2.0-Final
Operating System: Linux
Compatibility mode is enabled.
Indexing is enabled and 'autoconfig' parameter is set to true.
Reporter: Pavan Kundgol
Assignee: Adrian Nistor
Fix For: 7.2.4.Final, 8.0.0.Final
When a HQL query that involves string comparison operation with the empty string matching
is executed through hot rod client(java), it is resulting in the following error,
org.infinispan.client.hotrod.exceptions.HotRodClientException:Request for message id[7]
returned server error (status=0x85): org.hibernate.search.exception.EmptyQueryException:
HSEARCH000146: The query string '' applied on field 'CITY' has no
meaningful tokens to be matched. Validate the query input against the Analyzer applied on
this field.
The same problem may also occur when the string matching operation involves a string
containing certain special keywords(hibernate search stop words), as operands.
The problem seems to be assosiated with the the 'hibernate-hql-lucene' parser
used by the 'infinispan-remote-query-server' module. The problem here is that the
hibernate-hql-lucene parser is translating comparison operations directly into lucene
keyword matching operations, irrespective of the field type, though the phrase matching is
more appropriate for string fields. This leads to invalid query formation when the field
in concern is of type string, and is matched against an empty string(or a string
containing one or more hibernate search stop words).
For example,
the where condition city='' present in the following HQL query
select name from com.test.User where city=''
is tralated to lucene query, the hql-lucene parser is currently translating to
queryBuilder.keyword().onField("city").matching("").createQuery()
whereas recommended one is
queryBuilder.phrase().onField("city").sentence("").createQuery()
In the former way of translation, Hibernate Search query execution fails due to its usage
of standard analyzer while executing the query. Hence, the problem can also be avoided by
disabling the standard analyzer while executing the query.
queryBuilder.keyword().onField("city").ignoreAnalyzer().matching("").createQuery()
Preferred solution may be to enhance the 'hibernate-hql-lucene' library to do
type specific translations, and to specifically translate the string comparison operations
of hql query into phrase matching operations of lucene query(instead of keyword matching
operations).