Migrate to ANTLR Oracle MySQL Grammar [DBZ-8701]

[jpechane]

Migrated from DBZ-8701

In recent discussions with the ANTLR team, they plan to deprecate Positive Technologies MySQL grammar as it is not maintained and avoid multiple flavors of MySQL grammar. 

Details: [https://github.com/antlr/grammars-v4/pull/4412] 

[vsantonastaso]

@jpechane @Naros guys, I have a quick question regarding the MySQL grammar migration.
After importing the new .g4 files, I noticed that the generated lexer and parser classes now depend on two new base classes (MySQLLexerBase and MySQLParserBase, plus two related ones).
These provide runtime MySQL version detection and SQL mode handling.
The issue is that these base classes exist only in the grammars-v4 GitHub repository — they’re not published to Maven.
For now, I’ve copied the four Java files into our codebase, but this means we’ll need to manually sync changes whenever Oracle updates the grammar, and we’ll end up maintaining code that should ideally come from a proper dependency.
This isn’t specific to MySQL either the Oracle/PLSQL and Snowflake grammars use the same pattern, with custom base classes not available as Maven artifacts.
So I’m wondering whether it might be worth approaching the ANTLR community to propose publishing a grammars-v4-support artifact that bundles all these base classes, or possibly including them in the runtime artifact (similar to how it works for the PT grammar base classes). That would help not only us, but anyone using these grammars.
The alternative is simply accepting that copying these base classes locally is the expected approach.
What do you think, should we reach out to the ANTLR community, or stick with the copied files?

[jpechane]

I think we should involve @mike-lischke in the discussion.

[Naros]

I agree with @jpechane, but to be honest I wouldn't expect much churn on these if they follow the same pattern as the ones for Oracle PL/SQL. In fact the ones for Oracle PLS/SQL had been static since 2018 until I added a change last year Oracle 11 🤷 . But perhaps the MySQL ones have more churn, that IDK.