[Zope-dev] Idea: Create SQL-Alchemy tables via interfaces

[David Pratt]

You may wish to look at z3c.dobbin, though the issue I have found in my 
own experimentation, is with association tables for many to many 
relationships which throws in a wrench into this otherwise elegant 
solution. There may be something to around this in future.

Hermann Himmelbauer wrote:
> Hi,
> In my current SQLAlchemy / Zope-based design, I need the following:
> 
> - SQLAlchemy table definitions
> - classes + mappers
> - Zope interfaces
> 
> The problem with this design is that much data has to be defined twice, e.g. 
> the datatype "varchar(50)" should be represented by an interface with 
> TextLine(max_length="50"). Moreover, any changes such as adding columns etc. 
> also have to be done in the interface and the table definition.
> 
> To overcome this, I just had the idea to use the interface/schema definitions 
> for the table definition itself. Probably I'm not the first who had this 
> idea, but I'm not aware of such an extension to interfaces.
> 
> Any thoughts on this?
> 
> Best Regards,
> Hermann
>