On Mon, 22 Oct 2001, Max M wrote:
I basically have two zClassses. students and subjects. There can be many subjects, and in any subject there can be any number of students. .......
in such a case I will do it that way : each student_object will have a unique id, say "stu_01234" each subject_object will have a unique id, say "suj_56789" each student_object will have a list of subjects were he applied : ['suj_56789','suj_567','suj_512',...] if a subject is deleted you can protect your code by : creating a global_subject_list (permanet or dynamic) global_subject_list.has_key[a_subject] or you can write your own "delete_subject" fonction which will remove from student lists the delete subject the uniques ids act has an indirection allowing to modify the object without breaking any link .... -- _/ _/ _/_/_/ _/_/ Michel.Vayssade@UTC.fr Service Informatique _/ _/ _/ _/ T:33/0-3.44.23.49.24 Universite de Technologie _/ _/ _/ _/ F:33/0-3.44.23.46.77 BP 20.529 60205 Compiegne _/_/ _/ _/_/ _ mv@utc.fr __/www.utc.fr/~vayssade____ France