Sorry, that got cut off at the end.
class IssueTag(Base):
__tablename__ = 'issue_user_tag'
sqlalchemy.exc.InvalidRequestError: Table 'issue_user_tag' is already
defined for this MetaData instance. Specify 'extend_existing=True' to
redefine options and columns on an existing Table object.
On Thursday, November 15, 2012 7:32:29 PM UTC-5, Rob Crowell wrote:
>
> I'm working with a denormalized cache schema, and I've run into a
> situation where it would be helpful to be able to create multiple classes
> that extend Base but refer to the same __tablename__. Is this possible to
> do? I am getting this Exception:
> sqlalchemy.exc.InvalidRequestError: Table '[tablename]' is already
> defined for this MetaData instance. Specify 'extend_existing=True' to
> redefine options and columns on an existing Table object.
>
> For a little more insight, we have some attributes that always have
> exactly one value (user who created the issue), and other attributes that
> can have 1 or more values (user-defined tags for the issue). If we were
> being exhaustive, we would create two "cached" tables for our issues since
> sometimes we want to display recent issues sometimes by user and sometimes
> by tag:
> * issue_user
> * issue_tag
>
> However, we can get away with writing just one table and querying it with
> an appropriate group_by("user_id") to achieve the same end as having 2
> tables. Since my application should behave as if there were 2 separate
> cache tables (and I'd like to keep open the option of adding two separate
> cache tables in the future), I would like to have 2 different Base classes
> representing the two ways in which we would query the table. The obvious
> way of doing this doesn't work:
>
> class IssueUser(Base):
> __tablename__ = 'issue_user_tag'
>
> class IssueTag(Base):
>
>
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