Hey, I'm trying to validate some things on a self reference field, among them that a reference field on a table does not refer to the record where it is.
For instance, db.define_table('person', Field('name', length=256, unique=True, requires=IS_NOT_EMPTY()), Field('gender', requires= IS_IN_SET([T('Male'), T('Female')], zero=T('choose one'))), Field('father', 'reference person'), Field('mother', 'reference person'), format = '%(name)s' ) db.person.father.requires = IS_EMPTY_OR(IS_IN_DB(db(db.person.gender == 'Male'), db.person.id, '%(name)s', zero=T('choose one'))) db.person.mother.requires = IS_EMPTY_OR(IS_IN_DB(db(db.person.gender == 'Female'), db.person.id, '%(name)s', zero=T('choose one'))) So in addition to the gender restriction (yeah I know it's not always true, this is just an example), I'd like to add the restriction that a person cannot be it's own father or mother. Basically what I want is something like an IS_NOT_SELF or something. Any tips on how to go about this?