18 May
2010
18 May
'10
4:10 p.m.
Hi Eugen,
Looks like you are looking for an HQL query that returns a map of
(project -> list of steps) pairs which is not possible. The result set
is a flat structure. At most you can get a list of [project, step] arrays:
[p1, s1]
[p1, s2]
...
[p2, s1]
...
Why do you need to list all the projects with all their steps. Wouldn't
be better to choose the project from a list and then get the steps for
the selected project? Anyway, I don't see the need/usecase for a subquery.
Hope this helps,
Marius
On 05/18/2010 02:12 PM, Colesnicov Eugen wrote:
Hello everybody!
I need some help about construction of a subquery. I have 2 classes:
"projects" and "steps". Also, name of a projectclass pages - is one
of a
property of a class "step" (for this reason, If I know project, I can find
all steps of this project).
I have one query:
#set ($hql = ",
BaseObject as obj, StringProperty as prop where
(obj.name=doc.fullName and
obj.className='UAProjectManagementCode.ProjectClass' and obj.name not like
'%ClassTemplate') and
(obj.id=prop.id.id and prop.id.name='ProjectName')
order by prop.value asc
")
This query returns all projects. After this, I use
#foreach ($proj in $projs)
#set ($projDoc = $xwiki.getDocument($proj))
#set ($projName = $projDoc.getName())
...
And, each time, for each project, I use second query, with additional filter
by $projName:
#set ($hql2 = ",
BaseObject as obj, StringProperty as prop, StringProperty as otherprop
where
(obj.name=doc.fullName and
obj.className='UAProjectManagementCode.StepClass' and obj.name not like
'%ClassTemplate') and
(obj.id=prop.id.id and prop.id.name='Project' and
prop.value='$projName') and
(obj.id=otherprop.id.id and otherprop.id.name='Step')
order by prop.value asc, otherprop.value asc
")
Together, this construction returns to me list of all projects with all
params, and for each project - list of all steps with all params. This
construction works normal, but I know, that HQL give possibility to use
subqueries. It is a best variant, because now 2-nd query runs for each
project. If projects will be much more - speed will go down ... In a page
with HQL examples
(http://platform.xwiki.org/xwiki/bin/view/DevGuide/velocityHqlExamples)
unfortunately not exist any examples about subqueries in a XWiki. Can
somebody help me?
Thanks beforehand!
Eugen Colesnicov