Can't subtract offset-naive and offset-aware datetimes using bindparam

• asyncpg version: 0.23.0
• PostgreSQL version: postgres:11-alpine
• Do you use a PostgreSQL SaaS? If so, which? Can you reproduce the issue with a local PostgreSQL install?: I’m using docker image on a local machine
• Python version: 3.7.5
• Platform: mac
• Do you use pgbouncer?: no
• Did you install asyncpg with pip?: yes
• If you built asyncpg locally, which version of Cython did you use?:
• Can the issue be reproduced under both asyncio and uvloop?: I guess the event loop doesn’t really matter here

I have the following issue where I try to use bindparam to include a datetime with tzinfo in a select statement and then use it to insert in another table. This is a simplified version of the code (tested that it actually produces the error):

sel = select([User.id, bindparam("timestamp", datetime.datetime.utcnow().replace(tzinfo=datetime.timezone.utc))])
ins = insert(DeletedUser).from_select([DeletedUser.id, DeletedUser.timestamp], sel)
await conn.execute(ins)

which results in

sqlalchemy.exc.DBAPIError: (sqlalchemy.dialects.postgresql.asyncpg.Error) <class 'asyncpg.exceptions.DataError'>: invalid input for query argument $1: datetime.datetime(2019, 5, 16, 2, 49, 55... (can't subtract offset-naive and offset-aware datetimes)

DeletedUser.timestamp is of type timestamp with timezone info which I manually verified.

The following code works without any issues:

await conn.execute(insert(DeletedUser).values(id=5, timestamp=datetime.datetime.utcnow().replace(tzinfo=datetime.timezone.utc)))

Am I doing something wrong?

[hrist0stoichev]

Finally made it work… I guess sqlalchemy is just not inferring the type correctly. Sorry for opening the issue.

from sqlalchemy.types import TIMESTAMP

sel = select([User.id, bindparam("timestamp", datetime.datetime.now(datetime.timezone.utc), type_=TIMESTAMP(timezone=True))])
await conn.execute(sel)

[jhomsm]

Should this then reported as a sqlalchemy issue?

Looks like SQLAlchemy is well aware of this, as documentation is quite explicit:

In sqlalchemy.types.DateTime

For timezone support, use at least the TIMESTAMP datatype, if not the dialect-specific datatype object.

Also, in sqlalchemy.types.TIMESTAMP

TIMESTAMP datatypes have support for timezone storage on some backends, such as PostgreSQL and Oracle. Use the TIMESTAMP.timezone argument in order to enable “TIMESTAMP WITH TIMEZONE” for these backends