Thanks, Michael! Any thoughts on the autoload?
Thanks, Alyssa On Monday, November 30, 2015 at 11:43:30 AM UTC-8, Michael Bayer wrote: > > > > On 11/30/2015 02:29 PM, Alyssa Kwan wrote: > > Thanks Michael, > > > > These constructs are actually composed of 3 tables - the temporal data > > itself, a clock table, and an element clock table - both the clocks keep > > track of points in time that exist within time ranges since ranges are > > lossy. Does this advice still hold? > > yes, don't subclass SchemaItem :) Unless you're building out a > Postgresql extension and your own "CREATE" command that you could run > with psql (assuming that's not the case). > > > > A related requirement is the ability > > to autoload via reflection these constructs, for which I've created > > tables similar to INFORMATION_SCHEMA.TABLES and > > INFORMATION_SCHEMA.COLUMNS. I'm only concerned about operating on > > PostgreSQL. > > > > > > > What's the recommended way to approaching this? > > > > Thanks, > > Alyssa > > > > On Monday, November 30, 2015 at 10:26:28 AM UTC-8, Michael Bayer wrote: > > > > > > > > On 11/30/2015 12:54 PM, Alyssa Kwan wrote: > > > Hi, > > > > > > The problem I'm trying to solve is I've created a multi-temporal > > > relational table construct (à la bitemporality) that I want to > create > > > SQLAlchemy Core composite operations for (and eventually > > SQLAlchemy ORM). > > > > > > Let's call these TemporalRelationSet's. I've subclassed > SchemaItem. > > > > I'd not do that. If the thing you're dealing with is a Table, use > > Table. If you want to define a bunch of special operations > involving a > > certain Table and you're not able to use ORM, make a > > TemporalRelationSet > > of course, however, this is not a schema item. It would refer to > the > > Table you're dealing with. That is, prefer composition over > > inheritance. A SchemaItem is only intended to be the base of > objects > > that exist concretely within DDL. > > > > > > > > I > > > also do registration against a Registry class that I've subclassed > > > MetaData for, with a __visit_name__ of 'registry'. The idea is > that I > > > initialize a Registry, can register Table's against it, as well as > > these > > > TemporalRelationSet's. > > > > When your TemporalRelationSet is created, it can put memos inside of > > Table.info for its Table object; if you want things to happen when > that > > Table gets created, you can use the before_create / after_create > event > > listeners to handle this. > > > > > > > > > > Does this make sense for what I'm trying to do? > > > > > > If so, the specific problem I'm running into is create_all() on > > Registry > > > doesn't do anything. I started digging into the Visitable > > metaclass, but > > > hit a wall of understanding. > > > > Stick to the event API here, see the overview at > > > http://docs.sqlalchemy.org/en/latest/core/events.html?highlight=after_create#schema-events > > > < > http://docs.sqlalchemy.org/en/latest/core/events.html?highlight=after_create#schema-events>. > > > > > > > > > > > > > > > > > > I'm running Python 3.4.3 on OS X El Capitan with SQLAlchemy 1.0.9. > > > > > > Thanks! > > > Alyssa > > > > > > -- > > > You received this message because you are subscribed to the Google > > > Groups "sqlalchemy" group. > > > To unsubscribe from this group and stop receiving emails from it, > > send > > > an email to sqlalchemy+...@googlegroups.com <javascript:> > > > <mailto:sqlalchemy+unsubscr...@googlegroups.com <javascript:> > <javascript:>>. > > > To post to this group, send email to sqlal...@googlegroups.com > > <javascript:> > > > <mailto:sqlal...@googlegroups.com <javascript:>>. > > > Visit this group at http://groups.google.com/group/sqlalchemy > > <http://groups.google.com/group/sqlalchemy>. > > > For more options, visit https://groups.google.com/d/optout > > <https://groups.google.com/d/optout>. > > > > -- > > You received this message because you are subscribed to the Google > > Groups "sqlalchemy" group. > > To unsubscribe from this group and stop receiving emails from it, send > > an email to sqlalchemy+...@googlegroups.com <javascript:> > > <mailto:sqlalchemy+unsubscr...@googlegroups.com <javascript:>>. > > To post to this group, send email to sqlal...@googlegroups.com > <javascript:> > > <mailto:sqlal...@googlegroups.com <javascript:>>. > > Visit this group at http://groups.google.com/group/sqlalchemy. > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
