I haven't looked at that code in a bit, but I suspect that the right
thing happens if you just remove the association definition from
defclass and reevaluate the defclass form. Can you mark this as a bug
in elephant so I can remember to look into it later?
Thank you,
Ian
On Jul 4, 2008, at 4:24 AM, LukasGiessmann wrote:
hello,
since our last mail working with associations turned out to go quite
well
but one more problem came up:
i tried to change the associations by removing it and replacing it
by a
new association. but the function "remove-association" only works
partially.
1. in this one-to-one association the function doesn't work at all.
---
(defpclass job()
((title :initarg :title :accessor title-of :index t)
(company :initarg :company :accessor company-of :index t)
(job-holder :initarg :job-holder :accessor job-holder-of :associate
person)))
(defpclass person()
((name :initarg :name :accessor name-of :index t)
(job :initarg :job :accessor job-of :associate job)))
---
an error message shows up:
(remove-association *job1* 'job-holder *person1*) ; -> There is no
applicable method for the generic function #<STANDARD-GENERIC-
FUNCTION
ELEPHANT::OID (1)> when called with arguments (NIL).
same thing happens when i use the following statement:
(setf (job-holder-of *job1*) nil)
2. by one-to-many associations generally nothing happens at all.
---
(defpclass job()
((title :initarg :title :accessor title-of :index t)
(company :initarg :company :accessor company-of :index t)
(job-holders :accessor job-holders-of :associate (person job))))
(defpclass person()
((name :initarg :name :accessor name-of :index t)
(job :initarg :job :accessor job-of :associate job)))
---
it only works in this case:
---
(drop-instance *person2*)
(remove-association *job2* 'job-holders *person2*)
---
3. in the case of many-to-many associations everything goes fine.
how do i get the "remove-association" function to work?
are there other ways for changing associations?
thank you for your help
lukas
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