compile ":mongodb:3.0.3"
//runtime ":hibernate4:4.3.6.1"

environments {
    production {
        grails {
            mongo {
                replicaSet = [ "xxxxxxxx"]
                username = "xxxx"
                password= "xxxxxxxxxxxxxx"
                databaseName = "xxxxxx"
            }
        }
    }
    development {
        grails {
            mongo {
                replicaSet = [ "xxxxxxxx"]
                username = "xxxx"
                password= "xxxxxxxxxxxxxx"
                databaseName = "xxxxxx"
            }
        }
    }
    test {
        grails {
            mongo {
                replicaSet = [ "xxxxxxxx"]
                username = "xxxx"
                password= "xxxxxxxxxxxxxx"
                databaseName = "xxxxxx"
            }
        }
    }
}

package test

class Book {

    String name
    Map authors
    static hasMany = [authors:Author]

    static constraints = {
    }
}

package test

class Author {

    String name
    static constraints = {
    }
}

import test.*

def a = new Author(name:"Stephen King")

def book = new Book(name:"test")
book.authors = ["stephen":a]
book.save(failOnError:true)

{
    "_id": 1,
    "name": "test",
    "version": 0
}