use a composite primary key - just mark each column with 'primary_key=True'.
On Mar 12, 2007, at 2:28 PM, Mikkel Høgh wrote: > > Hi there, > > I'm trying to make a small (open source) inventory tracking system > with TurboGears and SQLAlchemy, and I have a little problem with how I > should implement the database part. > > I think the best idea would be to have different sequences for each > type of item tracked, so spork number 543 would be SPRK-00000543. > > Now, one could of course create a different table for each type of > item stored, but that means that creation of new types includes > modifications to the database structure and (even worse) the database > model. > > So I thought of just putting it all in a single table. The way I see > it, there's three different ways to do that, and I cannot discern > which is best: > 1) Use a normal int primary key and have item_number and item_type as > indexed columns > 2) Use a string primary primary key, containing the full item > designation (SPRK-00000543) > 3) Use a multi-column primary key with item_type and item_number > > The way I see it, #3 would be preferable, but is that possible with > SQLAlchemy - I can use UniqueConstraint to make sure the combination > is unique, but does that perform well, and can it be a primary key? > > In any case, I'm not decided yet, so if you have any advice on how to > best accomplish my goal, I'd appreciate if you'd help me :) > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
