[storm] psycopg2-2.2, Storm, and ENUMs

[Dan Halbert]

On Monday, May 24, 2010 11:35am, "James Henstridge" <james at jamesh.id.au> said:

> On Sat, May 22, 2010 at 3:06 AM, Dan Halbert <halbert at halwitz.org> wrote:
> > Psycopg2-2.2 now adds explicit casts to strings in places where it did not before.
> > ...
> > This change causes several storm tests to break for type conversion reasons.

*** That the above change caused the storm test breakage perhaps got lost in my following verbiage
and is probably the more important point. It will be necessary to fix the storm tests to work with psycopg2-2.2.

> The RawStr property type in Storm is really intended for use with
> binary data.  Given that the 2.x str type has essentially become the
> bytes type in Python 3, I wonder if the psycopg2 changes are treating
> it in a similar fashion?

I believe the psycopg2 change was not motivated by Python 3, but was to fix some different
problems. But you're right that the effect is to treat 2.x strings as bytes.
Here's the start of the thread on their list:
http://lists.initd.org/pipermail/psycopg/2010-April/006985.html

Storm treats any object for which isinstance(obj, str) is true as a psycopg2.Binary,
which psycopg2 now decorateswith a "::bytea".
(See to_database() in databases/postgres.py.)

> That said, If you are dealing with textual data (which the enumeration
> values essentially are), perhaps the Unicode type would have worked
> better.  Another option would be the Enum type, which lets you provide
> an arbitrary map between Python and database values.

In my case, I used a "CREATE TYPE" to create some string-based enums.
(The schema design predates my use of storm.)
When I passed these psycopg2 as RawStr's, psycopg2 used to leave these strings alone,
and PostgreSQL would coerce the string into the appropriate type.
But now psycopg2 decorates them with an explicit type, which doesn't match the column type.
So my RawStr() hack broke. Not a big deal, but I thought other people might run into the same
problem.

Dan
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