Yep, though possibly you'd want it on before-drop. You can actually handle both tasks in the same function if you like- the event name will be passed in as the first argument.
Randy Syring wrote: > Jason, > > Thank you for the response. Using the method you suggest, am I > understanding correctly that fks_for_sqlite() would only be run when a > create() was processed for that table? Also, I am assuming I would > need to create a complimentary function for handling the 'after-drop' > event. > > On Aug 22, 1:25 pm, jason kirtland <[EMAIL PROTECTED]> wrote: >> DDL() has some simple templating capabilities that can help out a bit >> here, but I'd suggest taking the ForeignKey code Mike provided as a >> start and putting together an after-create listener using >> Table.append_ddl_listener directly: >> >> http://www.sqlalchemy.org/docs/05/sqlalchemy_schema.html#docstrings_s... >> >> It would look something like: >> >> def fks_for_sqlite(event, table, bind): >> for c in table.c: >> for fk in c.foreign_keys: >> sql = your_code_to_make_trigger_for_fk(fk) >> bind.execute(sql) >> >> tbl.append_ddl_listener('after-create', fks_for_sqlite) >> >> Michael Bayer wrote: >>> you can build this functionality using the DDL() construct provided by >>> SQLAlchemy: >>> http://www.sqlalchemy.org/docs/05/sqlalchemy_schema.html#docstrings_s... >>> the ForeignKey objects on the table can be pulled out using: >>> for c in table.c: >>> for fk in c.foreign_keys: >>> do_something_with_fk(fk) >>> On Aug 22, 2008, at 11:19 AM, Randy Syring wrote: >>>> I would like sqlalchemy to generate triggers on an SQLite database to >>>> enforce foreign key relationships. The method is documented here: >>>> http://www.sqlite.org/cvstrac/wiki?p=ForeignKeyTriggers >>>> and I have written a foreign key trigger generator here: >>>> http://rcs-comp.com/site/index.php/view/Utilities-SQLite_foreign_key_... >>>> Although it does not recognize the kind of references sqlalchemy >>>> generates in the CREATE TABLE statements. >>>> Anyway, the point of this post is that I would like to know how I >>>> should go about extending sqlalchemy so that when I use ForeignKey >>>> constructs in the metadata, create statements on the tables would also >>>> create the triggers and drop statements on the tables would drop the >>>> said triggers to enforce the Foreign Key relationship. >>>> Thanks. > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
