[FIXED] How can I get objects based off of certain associations?

Issue

I have the following domain classes (Only trying to show what is needed to get the idea) :

class Scholarship {

   static hasMany = [grades:Grade]
}

and

class Grade {

   String id
   String description
}

In words I would like to, "Get all scholarships where the associated grade_id = myId". I would like to accomplish this using grails domain classes and not using sql. Any help appreciated

Solution

Are you looking for something like this?...

def results = Scholarship.withCriteria {
    grades {
        // myId must be defined somewhere above...
        idEq myId
    }
}

EDIT

A comment below adds to the original question and asks what if another relationship was expressed like this...

class Scholarship {
    static hasMany = [grades:Grade,majors:Major]     
}

The query I show above would still be exactly the same. The fact that there is a majors collection would not be relevant unless you wanted to include some attribute of Major to also be part of the criteria, which could look something like this...

def results = Scholarship.withCriteria {
    grades {
        // myId must be defined somewhere above...
        idEq myId
    }

    majors {
        // only return Scholarship instances which
        // contain a Major with the name 'Mechanical Engineering'
        eq 'name', 'Mechanical Engineering'
    }
}

I hope that helps.

Answered By - Jeff Scott Brown

Answer Checked By - Cary Denson (PHPFixing Admin)