On Aug 11, 2010, at 2:48 AM, Oatman wrote: > Jonathan, > > Thanks very much for you pointing out the reference keyword, that > solves the problem for self-referencing tables, but do you know of a > solution to my two-tables-referencing-each-other problem? I admit my > simplistic alias example could be solved very elegantly by a self- > referencing table, but I'd like to know how to do it with two tables, > if I wanted.
I'm pretty sure that the subject has come up on this list, but I don't recall when. I'm hoping that someone (Massimo when he comes up for air, perhaps) will chime in, and then we can add it to the manual section. I'm wondering, though, whether you can't use 'reference' in your first table to refer to the second one. > > Any thoughts? Thanks again > > On Aug 10, 7:16 pm, Jonathan Lundell <[email protected]> wrote: >> On Aug 10, 2010, at 10:55 AM, Oatman wrote: >> >> >> >> >> >>> Hi all, >> >>> How do I create two tables that both refer to each other? Here's a >>> simple example: >> >>> db.define_table( >>> 'item', >>> Field('current_alias', 'db.item_alias') >>> ) >> >>> db.define_table( >>> 'item_alias', >>> Field('name'), >>> Field('item', 'db.item') >>> ) >> >>> This throws >>> "SyntaxError: Field: unknown field type: db.item_alias for >>> current_alias" >>> because they both need the other to be created first! >> >>> How can I create a simple relationship like this? Thanks in advance! >> >> If the answer to this question is 'reference' >> <http://web2py.com/book/default/chapter/06?search=define_table#Self-Re...>, >> perhaps we could add a line or three in the manual section to explicitly >> mention forward references, and not only self references.
