sqlalchemy.exc.NoSuchModuleError: Can't load plugin: sqlalchemy.dialects:postgres

[kenn]

I’m getting this error from SQLAlchemy:

sqlalchemy.exc.NoSuchModuleError: Can't load plugin: sqlalchemy.dialects:postgres

turns out, the DB URL generated by Render is an obsolete one — now postgres: is deprecated, and should use postgresql: instead.

Context: python - sqlalchemy.exc.NoSuchModuleError: Can't load plugin: sqlalchemy.dialects:postgres - Stack Overflow

Will you fix this soon?

[al_ps]

Hi,

Thanks for reaching out.

SQLAlchemy is one of the only Postgres clients that enforces the postgresql:// scheme, most others will accept it along with postgres://. libpq of Postgres itself also accepts both (docs)

This is discussed at length in a GitHub issue here: https://github.com/sqlalchemy/sqlalchemy/issues/6083

A couple of workarounds could be:

• If you’re setting a database URL on your service manually, amend the scheme to postgresql:// when creating the env var.
• Or, of you’re getting a database env var setup via a Blueprint, then a small check in code may help, as suggested in the GitHub issue above.

However, I’ll raise this with the Datastores team.

Kind regards

Alan

[kenn]

Hi Alan,

Thanks for your response!

Actually, I faced the same problem the second time today with Retool, a trending Admin-as-a-Service app.

They take the DB URL string, and postgres: scheme failed, while manually modifying it to postgresql: worked.

So it’s not just SQLAlchemy, it’s more than that. I’m not sure if it’s a good trade-off worth saving 2 characters?

[al_ps]

Thanks for pointing out another case, however, I didn’t say SQLAlchemy was the only example. I’ll still be running this past our engineers, until then, you’ll need to add the ql manually.

Alan

[kate]

Hi Kenn,

Thanks for flagging this! We’ve just released an update to display Postgres connection URLs with a scheme of postgresql://, which should solve this issue. Thanks for using Render!

• Kate, Render PM