class UserProfile {
    String title
    String firstName
    String lastName
    static belongsTo = [user:User]
    static constraints = {
            user nullable:true , unique:true
            title nullable:true, blank:true
            firstName blank:false
            lastName nullable:true, blank:true
    }
}

class User {
    String username
    String password
    boolean enabled
    String email
    static constraints = {
        username size:6..40, blank:false, nullable: false, unique: true
        email email:true, size:6..40, blank:false, nullable: false, unique: true
        password size:5..64, password:true, blank:false, nullable: false
    }
    String toString(){username}
}

UserProfile.createCriteria().listDistinct({
    if(params.orderBy){
        if(params.orderBy=="email"){
        //the exception says that the element has no such property to both cases
            order("user.email", ascDesc)
            //order("email", ascDesc)
        }else{
            order("${params.orderBy}", ascDesc)
        }
    }

})

createAlias('user', 'u')