Hi, I'm just learning to use sqlalchemy now (although I've had some exposure to SQLObject and Django ORM, so not completely new to the game).
I'd like to address a standard ORM issue - i.e. interfacing Python Decimal objects with SQLite backend. It seems that sqlalchemy follows the standard strategy of passing the buck to sqlite, which converts fixed-point to floating point. If I may be pardoned a diversion... I understand why sqlite does this, but it constantly boggles my mind that ORM layers allow fixed<- >floating conversions. I have yet to find a single application where this is desirable behavior, since fixed-point generally goes along with guarantees of strict equality (I'm speaking here as a finance geek, money-handling being perhaps the preeminent real-world use of Decimals). Anyway, religious matters notwithstanding... although I'm comforted by sqlite's assurance that it tests identity out to 15 decimal places, which exceeds my own needs for precision... I would like to follow the recommendation of sqlalchemy, and guarantee strict precision by use of Decimal<->String<->Decimal conversions round-tripping to the database. I am looking at the sqlalchemy.types source code, and I like what I see... it looks not difficult to define what I want with AbstractType, UserDefinedType, TypeDecorator, etc. However, as a new user, the docstrings aren't completely clear. Can y'all give a hint to a newbie looking not to reinvent the wheel? Can I use TypeDecorator with impl=types.Numeric? If so, what do I need to override - bind_processor(), result_processor(), and/or what? I can't be the first person to want to do this. TIA for any pointers. -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalch...@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
