Fix: Add MariaDB-specific reflection

[tomkcook]

Description

Fixes: #521

This resolves #521 -- at least for me -- by adding a MariaDB-specific query for geometry column reflection.

Apologies that I am out of time today to add a test case. I'll look into it tomorrow.

Checklist

This pull request is:

• A documentation / typographical error fix
  • Good to go, no issue or tests are needed
• A short code fix
  • Please include: Fixes: #<issue number> in the description if it solves an existing issue
    (which must include a complete example of the issue).
  • Please include tests that fail with the main branch and pass with the provided fix.
• A new feature implementation or update an existing feature
  • Please include: Fixes: #<issue number> in the description if it solves an existing issue
    (which must include a complete example of the feature).
  • Please include tests that cover every lines of the new/updated feature.
  • Please update the documentation to describe the new/updated feature.

[tomkcook]

TBH I struggle a bit to articulate a test that would fail without this change and pass with it, at least within the current test regime. I can see two options:

• Set up a separate test_functional_mariadb.py that replicates most of test_functional_mysql.py but with a MariaDB database instead of a MySQL one.
• Write a test that exercises reflect_geometry_column() specifically, mock out the engine and check that the executed SQL includes the SRS_ID column if the dialect is MySQL but not if it's MariaDB.

Do the maintainers have a preference for which approach to take?

[adrien-berchet]

Hi @tomkcook,
Sorry for the delay, I'm currently on vacation.
Thank you very much for pointing this issue out and for proposing a solution. As far as I can see, your solution looks good but it could be reworked to be a bit more compact and to avoid duplicated code. And for your question, I think that just one test for reflect_geometry_column is enough.
I will have some time next week to review this more carefully.

[adrien-berchet]

Hi @tomkcook !
I made a few tests in #524 and I realized that MariaDB was not as close to MySQL as I expected, so I think it should be processed as a complete different dialect. Nevertheless, there is something I don't understand: I could not find a way to insert a geometry using a WKB string, is it possible? Otherwise we will have to convert all WKB strings into WKT strings, which is quite bad for perf.