I have been thinking about this. How can one tell if the resulting records are going to have fields from multiple tables?.
On Jan 30, 12:01 am, Massimo Di Pierro <[email protected]> wrote: > Immagine you have the following (suggested by user Nik): > > db.define_table('person',Field('name'),format='%(name)s') > db.define_table('company', Field('name'),format='%(name)s') > db.define_table('member',Field('person',db.Person), > Field('company',db.company)) > > and a new table > > db.define_table('manager', Field('member',db.member)) > > Now you may want to a validator for managers with names of possible > people who are members of the company. > You can do it in this way (allowed): > > db.manager.member.requires=IS_IN_DB(db,'member.id',lambda row: '% > (name)s' % db.person[row.person]) > > It would be nice to be able to also use this alternative syntax (not > yet allowed): > > db.manager.member.requires=IS_IN_DB(db(db.member.person==db.person.id),'member.id','% > (person.name)s') > > This is not yet possible but would be better because it would use a > join instead of one select per option. Want to larn web2py? Try > understand the IS_IN_DB validator in gluon/validators.py and implement > the proposed syntax above.
