I have a BBDD table with XMLType column ("atributos") for Oracle 10g, and HQL with Xpath not works.

The xml structure:

<atributos>
<atributo id="1" valor="6"/>
<atributo id="52" valor="1"/>
<atributo id="51" valor="1"/>
<atributo id="6" valor="1"/>
</atributos>

My query:

SELECT extractValue(d.atributos, '/atributos/atributo[@id=\"52\"]/@valor')
from DocumentacionServicio d

My Exception:

java.lang.IllegalStateException: No data type for node: org.hibernate.hql.ast.tree.MethodNode
\-[METHOD_CALL] MethodNode: '('
+-[METHOD_NAME] IdentNode: 'extractValue' {originalText=extractValue}
\-[EXPR_LIST] SqlNode: 'exprList'
+-[DOT] DotNode: 'documentac0_.ATRIBUTOS' {propertyName=atributos,dereferenceType=4,propertyPath=atributos,path=d.atributos,tableAlias=documentac0_,className=es.abertis.iu.entity.DocumentacionServicio,classAlias=d}
| +-[ALIAS_REF] IdentNode: '(documentac0_.ES_T1, documentac0_.ID_DOCUMENTACION_SERVICIO)' {alias=d, className=es.abertis.iu.entity.DocumentacionServicio, tableAlias=documentac0_}
| \-[IDENT] IdentNode: 'atributos' {originalText=atributos}
\-[QUOTED_STRING] LiteralNode: ''/atributos/atributo[@id=\"52\"]/@valor''


Where is the problem?

Thanks
Dave