Comparing Properties in hasMany Criteria - grails

Question

I have a domain classes like so:
class Person {
Team team
static hasMany = [history: PersonHistory]
}
class PersonHistory {
Team team
Person person
}
Now I would like to create a criteria that pulls back all the 'persons' who have a PersonHistory instance with a different team.
Something along the lines of:
def c = Person.createCriteria()
def experiment = c.list {
history {
neProperty("team", history.team)
}
}
However this is throwing (because of the history.team):
Missing Property Exception
No such property: history for class: grails.orm.HibernateCriteriaBuilder
Can I do this inside one criteria query? If so, how?

Answer 1

I haven't test it but I think this should work:
Person.withCriteria {
createAlias 'history', 'h'
ne 'team', h.team
}
You have to create an alias for the join with history.
EDIT:
Now I got it! With the following sample data:
def t1 = new Team(name: 'team 1').save()
def t2 = new Team(name: 'team 2').save()
def t3 = new Team(name: 'team 3').save()
def p1 = new Person(team: t1).save()
def p2 = new Person(team: t1).save()
def p3 = new Person(team: t2).save()
def p4 = new Person(team: t2).save()
def p5 = new Person(team: t3).save()
def ph1 = new PersonHistory(person: p1, team: t1).save()
def ph2 = new PersonHistory(person: p2, team: t3).save() // t3 instead of t1
def ph3 = new PersonHistory(person: p3, team: t2).save()
def ph4 = new PersonHistory(person: p4, team: t1).save() // t1 instead of t2
def ph5 = new PersonHistory(person: p5, team: t3).save(flush: true)
Now you can execute the following criteria:
List<Person> persons = PersonHistory.withCriteria {
createAlias 'person', 'p'
neProperty 'p.team', 'team'
projections {
property 'person'
}
}
That will return the correct persons p2 and p4