Hi everyone, I'm new to SQLSoup and only have a little sqlalchemy experience and I'm wondering if anyone can give me some direction on how to use the subclassed sqlsoup object outlined in previous posts. I also have more than a few talbes with no primary keys that I need dynamically mapped to objects.
Could anyone point me to a basic query and connection structure that utilizes the sub-classed object? Thanks! On Monday, March 4, 2013 3:32:44 PM UTC-5, brent wrote: > > > > On Monday, 4 March 2013 12:31:51 UTC-7, Michael Bayer wrote: >> >> you can control the whole thing using map_to(): >> https://sqlsoup.readthedocs.org/en/latest/api.html#sqlsoup.SQLSoup.map_to, >> however that would mean you'd need to build the Table reflection outside >> of calling that in any case. >> >> Another approach might be just to subclass the SQLSoup object and >> override the map_to() method, so that you reflect "tablename" ahead of >> time, then pass it in as "selectable": >> >> >> class MySoup(SQLSoup): >> def map_to(self, attrname, tablename=None, …): >> table = Table(tablename, self._metadata, Column('name', String, >> primary_key=True), autoload=True, autoload_with=self.bind) >> return super(MySoup, self).map_to(attrname, selectable=table, …) >> >> There should be some more event hooks in SQLAlchemy for intercepting the >> primary key. We currently have hooks to intercept columns as they are >> reflected, but not the actual PK column collection. >> >> >> > ok, that's simpler than what I did. > > >> >> >> >> >> >> On Mar 4, 2013, at 2:16 PM, brent <bped...@gmail.com> wrote: >> >> >> >> On Monday, 4 March 2013 11:57:01 UTC-7, Michael Bayer wrote: >>> >>> Have you looked at SQLSoup ? This library already does exactly what >>> you're looking for. >>> >>> https://sqlsoup.readthedocs.org/en/latest/ >>> >>> >> wow! yeah that does do what I'm looking for. >> However, I'm mapping to tables that do not have primary keys defined. So >> with SQLSoup, I get: >> >> sqlsoup.SQLSoupError: table 'cpgIslandExt' does not have a primary >> key defined >> >> I got the same in sqlalchemy if I don't explicitly add the name column to >> the db. Any way around this? >> >> >>> For the most part, I have this working. However, the example in the gist >>> shows that: >>> >>> len(g.cpgIslandExt.all()) != g.cpgIslandExt.count() >>> >>> >>> What does your SQL echo output say? Looking at the queries (and the >>> rows returned, if you use echo='debug') will illustrate what's being sent. >>> >>> A typical reason why all() returns fewer rows is when the query returns >>> duplicate primary key identities - returned objects are uniqued on identity >>> as they are received. The fact that the "name" column is being hardcoded >>> in your base model as the sole "primary key" for all mappings is the likely >>> cause of this even being possible. The reflection process already knows >>> how to yield the primary key constraints defined on each table so you'd >>> best rely upon that. >>> >>> >>> >>> >>> >>> >>> >> -- >> 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. >> To post to this group, send email to sqlal...@googlegroups.com. >> Visit this group at http://groups.google.com/group/sqlalchemy?hl=en. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> >> >> >> -- 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/groups/opt_out.
