hello, thank you for the fast answer everything worked out perfectly. i was busy with writing exams, so it took me some time to figure everything out. but as i said before the associations are all performing well now thanks to you.
take care lukas > Hi Lukas, > > Were you able to try this example again using the latest checkin? > Early feedback is better than later! > > Thanks, > Ian > > On Jun 17, 2008, at 3:23 PM, LukasGiessmann wrote: > >> hello, >> >> just in case you're wondering why i'm coming up with questions >> concerning >> marc's topic "associations in the elephant system", i'm trying to >> assist >> him with this topic, so there might be several questions coming up >> in the >> next time - hope you don't mind. >> to get straight to the point: >> >> 1) >> i tried to work with the last person/job example and the new >> association >> slots, so i made the following example: >> >> --- >> (defpclass job() >> ((title :initarg :title :accessor title-of :index t) >> (company :initarg :company :accessor company-of :index t))) >> >> (defpclass person() >> ((name :initarg :name :accessor name-of :index t) >> (job :initarg :job :accessor job-of :associate t))) >> >> >> (defvar *max-persons* 500) >> (defvar *max-jobs* 100) >> >> (defun make-instances () >> (with-transaction () >> (dotimes (i *max-jobs*) >> (let ((current-job (make-instance 'job :title (string (gensym)) >> :company (string (gensym))))) >> (dotimes (j (/ *max-persons* *max-jobs*)) >> (make-instance 'person :name (string (gensym)) :job current- >> job)))))) >> --- >> >> after the call of make-instances there are 100 jobs and for every job >> there exist 5 persons. >> but i have still the following problem: >> how can i get all persons which associate a certain job by using the >> instance of the job which should be associated by the persons. >> i thought on something like: >> >> --- >> (defvar *obj* (first (get-instances-by-class 'job))) >> (get-instance-by-value 'person 'job *obj*) >> --- >> >> >> 2) >> what is the better way for using association slots in your opinion, >> the one of the example above or a special class which contains only >> associations of jobs and persons? >> >> --- >> (defpclass p-j-assoc() >> ((job :initarg :job :accessor job-of :associate t) >> (person :initarg :person :accessor person-of :associate t))) >> --- >> >> >> 3) >> how do i work with many-to-many association slots, since it is not >> possible for me to assign a value to the slot. >> >> thank you in advance. >> >> >> best regards >> >> lukas >> >> _______________________________________________ >> elephant-devel site list >> elephant-devel@common-lisp.net >> http://common-lisp.net/mailman/listinfo/elephant-devel > > _______________________________________________ > elephant-devel site list > elephant-devel@common-lisp.net > http://common-lisp.net/mailman/listinfo/elephant-devel > _______________________________________________ elephant-devel site list elephant-devel@common-lisp.net http://common-lisp.net/mailman/listinfo/elephant-devel
