Add visit_try_cast to sqlalchemy compiler

[dwolfeu]

Description

I have added a visit_try_cast() method to trino.sqlalchemy.compiler.TrinoSQLCompiler. This fixes issue 473.

Non-technical explanation

This allows Trino's try_cast() to be used in SQLAlchemy.

Release notes

(x) This is not user-visible or docs only and no release notes are required.
( ) Release notes are required, please propose a release note for me.
( ) Release notes are required, with the following suggested text:

[cla-bot]

Thank you for your pull request and welcome to the Trino community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. Continue to work with us on the review and improvements in this PR, and submit the signed CLA to cla@trino.io. Photos, scans, or digitally-signed PDF files are all suitable. Processing may take a few days. The CLA needs to be on file before we merge your changes. For more information, see https://github.com/trinodb/cla

[dwolfeu]

I just emailed the signed CLA.

[hovaesco]

Thanks for your contribution! Could you please add a test for it?

[dwolfeu]

Sure! I should add one here, right?

[hovaesco]

Sure! I should add one here, right?

Yes, correct.

[cla-bot]

Thank you for your pull request and welcome to the Trino community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. Continue to work with us on the review and improvements in this PR, and submit the signed CLA to cla@trino.io. Photos, scans, or digitally-signed PDF files are all suitable. Processing may take a few days. The CLA needs to be on file before we merge your changes. For more information, see https://github.com/trinodb/cla

[dwolfeu]

Thanks for your contribution! Could you please add a test for it?

I have added a unit test.

[dwolfeu]

@hovaesco My CLA has been processed.

[hovaesco]

@cla-bot check

[cla-bot]

The cla-bot has been summoned, and re-checked this pull request!

[hashhar]

@dwolfeu Please make test conditional to run only with SQLAlchemy 2.x since it seems 1.x doesn't have try_cast? (or maybe it needs to be imported differently?).

[dwolfeu]

@dwolfeu Please make test conditional to run only with SQLAlchemy 2.x since it seems 1.x doesn't have try_cast? (or maybe it needs to be imported differently?).

@hashhar Thanks for reviewing this PR. I have added an exception to the unit test. Three tests still fail, but that seems to be unrelated to my changes.

[hashhar]

thanks, those are indeed unrelated.

@hovaesco can you help take a look at the types-all installation failure (seems it's been unmaintained for very long) - https://github.com/asottile-archive/types-all for the CI checks step.

The PyPy failures we can tackle separately since it's about Kerberos + PyPy incompat.

[dwolfeu]

@hashhar @hovaesco Would it be possible to resolve this PR by the weekend or is that being too impatient?

[hashhar]

I've squashed (logically a single change) and rebased on master (to fix CI).

Will merge, sorry for the slow work.

[hashhar]

Fixed some linter errors.

[dwolfeu]

I've squashed (logically a single change) and rebased on master (to fix CI).

Will merge, sorry for the slow work.

Not at all! Thank you for the collaboration. :)