These are just sample names. In reality they are separate business/use case entities sharing only the same supertype, they are not enumerated.
Am Donnerstag, 11. September 2014 15:42:47 UTC+2 schrieb Richard: > > Why component_a, _b, _c... You will end up create new table all the time... > > Richard > > On Thu, Sep 11, 2014 at 7:04 AM, Jan Beilicke <[email protected] > <javascript:>> wrote: > >> Hi everyone, >> >> I'm working on a web2py project which requires a complex relationship >> model. I want to use a model that works well with web2py's DAL and I would >> be glad if somebody could point me into the right direction. >> >> I created a small sample ER diagram to illustrate my problem, only the >> important parts are displayed and the table names are generalized for >> easier understanding. The database has a couple of tables (or business >> objects), most of them are depending on some supertype, let's call it >> 'component_type', the subtypes 'component_[a-z]'. >> >> The business case requires to create a component_package which contains >> required components, but *all components in the package must be of the >> same component_type.* >> >> Two possible variants are shown in the illustration: >> >> Variant A: The component_package contains the foreign keys of the >> component tables. >> Variant B: The package additionally contains the foreign key of the >> component_type table. >> >> Which variant would you recommend and which one might work better with >> DAL? Unfortunately, all the resources and database design documents I found >> in the web were only explaining the general supertype/subtype relation. >> >> Thank you in advance and >> kind regards, >> >> Jan >> >> >> <https://lh3.googleusercontent.com/-zgZdMMjkmwg/VBF_6_5O2FI/AAAAAAAAAYc/PXyEaTB32iQ/s1600/relation_problem.png> >> >> -- >> Resources: >> - http://web2py.com >> - http://web2py.com/book (Documentation) >> - http://github.com/web2py/web2py (Source code) >> - https://code.google.com/p/web2py/issues/list (Report Issues) >> --- >> You received this message because you are subscribed to the Google Groups >> "web2py-users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- You received this message because you are subscribed to the Google Groups "web2py-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
