I do not recommend anyone to actually use this. This is just horrible. > If I only need many2many in one directions I use the list:reference > and I cache the query that maps the id into the representation of the > corresponding record.
Then why are you not using the database types that are actually designed for this? ARRAY comes to mind. -- Thadeus On Thu, Aug 12, 2010 at 12:42 PM, mdipierro <[email protected]> wrote: > True but joins are expensive. > > > Massimo > > On Aug 12, 11:10 am, Thadeus Burgess <[email protected]> wrote: >> ew >> >> jaywalking should never be a replacement for joins... >> >> -- >> Thadeus >> >> On Thu, Aug 12, 2010 at 2:42 AM, mdipierro <[email protected]> wrote: >> > Yes, if you use any validator IS_IN_SET or IS_IN_DB with >> > multiple=True >> >> > I think it is still very convenient and can simplify some of your >> > code. Yet on RDBS you can do joins and this should be used a >> > replacement for that. >> >> > On Aug 11, 9:51 pm, Jason Brower <[email protected]> wrote: >> >> Should i worry about this on my setups with sqlite but i do not use gae? >> >> Almost all my setups are sqlite but on apachi fcgi. >> >> Best regards, >> >> jason >> >> >> ----- Original message ----- >> >> > There was a problem with this which is now fixed. >> >> > This is a very important feature if you plan to develop locally >> >> > (sqlite) and deploy on GAE. >> >> >> > Massimo >> >> >> > On Aug 10, 4:18 am, mdipierro <[email protected]> wrote: >> >> > > Experimentally there is a new feature in trunk. >> >> >> > > Field('name','list:string') >> >> > > Field('name','list:integer') >> >> > > Field('name','list:reference other table') >> >> >> > > and new operators >> >> >> > > db.mytable.myfield.contains(4) >> >> >> > > which works for list:reference, list:integer, list:string, string and >> >> > > text types. >> >> >> > > The list: type are mapped differently on RDBS ([1,2,3]->'|1|2|3|') and >> >> > > on GAE (uses a string list propery). It is backward compatible with >> >> > > data stored using the IS_IN_DB(...,multiple=True). So here is an >> >> > > example of a program: >> >> >> > > # model >> >> > > db.define_table('product',Field('name'),format='%(name)s') >> >> > > db.define_table('purchase',Field('code'),Field('products','list:reference >> >> > > product')) >> >> >> > > # controller >> >> > > def products(): >> >> > > db.product.id.represent=lambda id: A('click >> >> > > me',_href=URL('purchases_by_product',args=id)) >> >> > > return >> >> > > dict(form=crud.create(db.product),items=db(db.product.id>0).select()) >> >> > > def purchases(): >> >> > > return >> >> > > dict(form=crud.create(db.purchase),items=db(db.purchase.id>0).select()) >> >> > > def purchases_by_product(): >> >> > > product_id=request.args(0) >> >> > > return >> >> > > dict(items=db(db.purchase.products.contains(product_id)).select()) >> >> >> > > Now register some products. When you try register purchases you should >> >> > > automatically get a SELECT window with product names. The list of >> >> > > items should also show a comma separated list of product names. >> >> >> > > I have not tested this on GAE. I could use some tests. Please let me >> >> > > know. >> >> >> > > Massimo >
