thanks a lot michael. i think i'll go this way :)
best regards, alex On 07/07/2012 05:13 PM, Michael Bayer wrote: > sure engine and connection have .dialect.name. Foreign key constraints > don't matter on SQLite unless you've actually enabled them, which is rare. > I'd still use an event though so at least the behavior is transparent. > > @event.listens_for(my_table, "before_create") > def add_fk(table, conn, **kw): > if conn.dialect.name != 'mssql': > table.append_constraint(ForeignKeyConstraint(...)) > > tricky though to modify the table metadata within a "create" event in the > case that the table is created multiple times in an app. you can put a flag > in table.info, like "table.info['added_the_fk'] = True", to keep track of > things. > > > > On Jul 7, 2012, at 12:59 AM, alex bodnaru wrote: > >> >> hello mike and thanks for your answer. >> >> no problem with ForeignKeyConstraint, but wouldn't AddConstraint go the alter >> way? in this case, it will be ignored by the sqlite dialect. >> >> what i was looking for was more like: >> >> from sqlalchemy... import get_dialect >> >> .... >> fk_parms = dict(.....) >> if get_dialect() != 'mssql': >> fk_parms.update(onupdate='restrict') >> fk = ForeignKey(**fk_parms) >> >> would the dialect be accessible from the engine, metadata etc? >> >> thanks in advance, >> alex >> >> >> On 07/06/2012 11:39 PM, Michael Bayer wrote: >>> you'd use ForeignKeyConstraint along with the AddConstraint directive, and >>> limit it per-dialect using create/drop events as documented at >>> http://docs.sqlalchemy.org/en/rel_0_7/core/schema.html#controlling-ddl-sequences >>> . >>> >>> >>> On Jul 6, 2012, at 1:30 PM, alex bodnaru wrote: >>> >>>> >>>> hello friends, >>>> >>>> i need to define a foreign key differently for different dialects: >>>> ondelete='restrict' for most engines, but nothing (implied and not >>>> recognized) >>>> for mssql. >>>> >>>> could you help? >>>> >>>> thanks in advance, >>>> alex >>>> >>>> -- >>>> 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 >>>> sqlalchemy+unsubscr...@googlegroups.com. >>>> For more options, visit this group at >>>> http://groups.google.com/group/sqlalchemy?hl=en. >>>> >>> >> >> -- >> 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 >> sqlalchemy+unsubscr...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/sqlalchemy?hl=en. >> > -- 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 sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
