Forgot this link : http://web2py.com/book/default/chapter/07#One-form-for-multiple-tables
On Tue, Nov 8, 2011 at 4:04 PM, Richard Vézina <[email protected]>wrote: > Hello Daniel, > > I suggest you to normalized your schema before using feature like > list:reference that impose denormalisation to work... If your model is only > a bit complexe you will be rapidly always making trade off between ease of > implementation of interface with web2py feature and good design > practices... Web2py allow ease prototyping that pretty nice if you follow > the concept of one table - one form, but you have to build your own complex > controllers functions for complex schema to follow good design practices > don't fall into the pit of rapid gain at interface level because you will > pay the price later for sure... You will have to refactor your model and > your app and migrate data into new schema... That one side... > > > The other side... > Agile tell that you should rapidly prototyping system that respond to the > need before any thing else and web2py allow you to develop really fast... > So... You maybe have to keep in mind that you will have to refactor to > respond you client need rapidly. The problem you will face is that your > client will start to ask questions when, because of refactoring, you will > tell him that new feature will take a lot more time... > > For sure many to many relation need custom form build with SQLFORM.factory > or helpers... Also if you want SQLFORM.factory to work pay attention to the > name of your primary key (don't use the same name for pk and fk) and > duplicate field name in the differents tables you have because _filter_fields > function will fail... > > Hope it helps. > > Richard > > On Tue, Nov 8, 2011 at 1:18 PM, demetrio <[email protected]> wrote: > >> Hi everyone, >> >> i'm starting a new project with web2py, and now i'm defining the model >> of the app and i have some questions. >> >> the "classical" and simplified model (there are lots of tables but the >> questions are about those) is something like: >> >> Table 'companies' >> - id_company >> - name >> - .... >> >> Table 'guild' >> - id_guild >> - name >> - .... >> >> Table 'construction' (i don't really know if "construction" is the >> correct english word for this example, or maybe "building_lot") >> - id_construction >> - name >> - .... >> >> And now I have to make the relations. In this case one companies can >> have many guilds (i.e: the company 'company1' owns to the 'painters' >> guild and the 'doors' guild). This relation would be easy in web2py >> with a list:reference. >> >> But the case is that in a building lot, can have one company working >> with an specific guild, and in other building lot, the same company >> working with another guild. >> >> For example: >> In the construction "A" of 5 apartments, the company "company1" >> only works installing windows. >> In the construction "B" of 20 apartments, the company "company1" >> only works painting the walls. >> >> In a classic table_has_table model, I could have this: >> >> Table "company_has_guild": >> - id_company_has_guild >> - id_company >> - id_guild >> >> And: >> >> Table "construction_has_company_has_guild" (and at this moment don't >> know if this is the best way to make this relation...) >> - id_construction >> - id_company_has_guild >> >> As I have mentioned before, the first relation (company_has_guilds) >> with web2py would be easy: >> >> db.define_table("guilds", >> Field("name", "string") >> ) >> >> db.define_table("company", >> Field("name", "string"), >> Field("guilds", "list:reference guilds") >> ) >> >> Any suggestions about the creation of the second relation >> (construction_has_company_has_guild)? Or I have to create the >> "classic" table_has_table model? In this case, there is some efficient >> way to make it in web2py? >> >> Thanks in advance! >> Daniel > > >
