Help with Creating Models for Views
I am trying to create a Model to pass to a gsp view. I would like to do a sub query across two tables. I have two domains, alum_profile and alum_position. alum_profile has many alum_position's. alum_position belongs to alum_profile. In SQL if I wanted to create a result set, I would have something like this:
Select count(id),
(Select CONCAT(first_name, ' ', last_name)
From alum_profile
where
alum_profile_id =alum_profile.id ) as Person
FROM alum_position
开发者_运维百科 GROUP BY alum_profile_id
ORDER BY count(id) DESC
How do I do this with HQL and create a model that can be passed to a gsp View.
Thanks for your help jason
I am using Spring Source, with MySQL and writing in groovy on grailsFrom what I've read of your question, you want to display a list of the Profile's names, along with how many Positions each Profile has, sorted by the number of positions, desc.
First, you need Models:
class AlumProfile {
String first_name
String last_name
def hasMany = [positions: AlumPosition]
};
class AlumPosition {
String name // I just added this, no idea what you need in here
def belongsTo=AlumProfile
};
Now you want to create a list of the AlumProfiles sorted by position count. In your controller, you need:
def allByPositionCount = {
def profiles = AlumProfile.list().sort( [compare: { a,b -> a.positions.size().compareTo( b.positions.size() ) }] as Comparator );
[ profiles: profiles ]
}
This will render the allByPositionCount.gsp with the model containing the "profiles" member that is the list of profiles in the correct order, so something like:
<g:each in="${profiles}" var="profile" >
${profile.first_name} ${profile.last_name} has ${profiles.positions.size()} positions
</g:each>
should render what you want.
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