Grails GORM on multiple Forms

Usually I'm using One-to-many relationship by this way :

class Study {
    static hasMany = [ crfs : Crf ]
    String name 
    ...
} 

class Crf { 
String title
String info 
...
} 

I can extend this relationship to others domains, Ex :

static hasMany = [ crfs : Crf, crfb : CrfBlood ...]

But in my case I have to link the Study domain to 30 others d开发者_JAVA技巧omains, maybe more...(ex : CrfBlood, CrfMedical, crfFamily, etc...).

What domain model implementation should I use in my case ?

I would like to keep the dynamic finders usability in my project.

Update - model complement :

A Study can have one-to-many Subject.

A Study can have one-to-many Crfs (ex : CrfBlood, CrfMedical, crfFamily, etc...).

A Subject can have one-to-many Visit (ex : a subject can have several Blood testing).

I would like to dynamically assign Crfs to a Study, so how can I use GORM (dynamic finders) without using static hasMany = [...] in my domain ?

Maybe, I can implement a service to do the same stuff did by hasMany ?

You can declare all Crf types as subclasses of Crf, so that you'll only have one relationship to Study, but still be able to add the different types.

class Crf {
    String title
    String info
}

class CrfBlood extends Crf {
    String detailBlood
}

class CrfMedical extends Crf {
    String detailMedical
}

class Study {
    String name
    static hasMany = [ crfs: Crf ]
}

Then you can do:

def s = new Study(...)
def c1 = new CrfBlood(...)
def c2 = new CrfMedical(...)
s.addToCrfs(c1)
s.addToCrfs(c2)