id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
154	Can't delete object with ManytoMany Relationship	Dobbes	Adrian Holovaty	"If you have an object with a manytomany relationship you can't delete it within the admin interface. As it spits out this error.

{{{
Traceback (most recent call last):

  File ""/home/punteney/dobbes.com/django/core/handlers/modpython.py"", line 214, in get_response
    return callback(request, **param_dict)

  File ""/home/punteney/dobbes.com/django/views/admin/main.py"", line 1057, in delete_stage
    obj.delete()

  File ""/home/punteney/dobbes.com/django/core/meta.py"", line 57, in _curried
    return args[0](*(args[1:]+moreargs), **dict(kwargs.items() + morekwargs.items()))

  File ""/home/punteney/dobbes.com/django/core/meta.py"", line 760, in method_delete
    cursor.execute(""DELETE FROM %s WHERE %s=%%s"" % (opts.db_table, opts.pk.name), [getattr(self, opts.pk.name)])

  File ""/home/punteney/dobbes.com/django/core/db/base.py"", line 10, in execute
    result = self.cursor.execute(sql, params)

IntegrityError: ERROR:  update or delete on ""blog_entries"" violates foreign key constraint ""$1"" on ""blog_entries_categories""
DETAIL:  Key (id)=(2) is still referenced from table ""blog_entries_categories"".

DELETE FROM blog_entries WHERE id=2
}}}

This is from trying to delete a blog entry that is tied to the categories. The line in the Entry model is:

{{{
meta.ManyToManyField(Category, filter_interface=meta.HORIZONTAL),
}}}

I can't remove the category linking before I delete it as it is a required field so it comes back with an error message saying that the field is required."	defect	closed	contrib.admin		normal	fixed			Accepted	0	0	0	0	0	0