If all you're looking for is an implicit generation of an IDENTITY column, you can use the autoincrement=True keyword to the Column constructor.
But be careful with the assumption of autoincrementing PKs. It's perfectly valid to have a PK that is not autoincrementing. That's why the pseudo-Sequence() mechanism is there in the first place, to distinguish between the two (and to allow the specification of the IDENTITY seed value). Issuing a spurious "SELECT @@IDENTITY" could be construed as a bit risky as well -- that will simply return the last inserted IDENTITY value on that DB connection -- which could be from a completely different query. Given that SA pools connection, it seems to me that this is bad-tasting recipe. I'm not sure I understand the motivation to check each query anew for identity keys. What's wrong with checking for them only at table definition time? Rick On 1/9/07, Paul Johnston <[EMAIL PROTECTED]> wrote: > > > Hi, > > Using MSSQL, session.flush() doesn't always fetch primary keys back from > the database. It works if you explicity specify a sequence, but if the > sequence is implicitly created it doesn't fetch. I have raised ticket > #415 for this issue. > > In MSSQLExecutionContext, it looks to see if any column has a sequence, > and if so issues "select @@identity" afterwards. A couple of simple > solutions to this: > 1) Always issue "select @@identity" (quick tests show this should be safe) > 2) Copy the code from MSSQLSchemaGenerator that determines whether to > create an implicit sequence, and run it for each query. > Thing is, I'm a bit worried about the performance of both those options. > > I'm wondering why the decision to give a column an implicit sequence is > in the database engine code. The fix that seems logical to me is to put > the code to create an implicit sequence in Column.__init__. It's down to > the individual engines how they implement this sequence, but its > existence or not is engine independent. > > Let me know what you think, > > Paul > > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
