feat: enhance ALTER TABLE support with UNIQUE KEY and INVISIBLE index

[minleejae]

Description

This PR adds support for two MySQL DDL statements:

ALTER TABLE ADD CONSTRAINT UNIQUE KEY syntax
ALTER TABLE ALTER INDEX INVISIBLE syntax

Problem Solved

Previously, JSqlParser couldn't properly parse the following SQL statements:

ALTER TABLE sbtest1 ADD CONSTRAINT UNIQUE KEY ux_c3 (c3);
ALTER TABLE sbtest1 ALTER INDEX c4 INVISIBLE;

These are valid MySQL syntax for adding a unique constraint with a custom name and for making an index invisible to the query optimizer while keeping it maintained.

Related Issue

#2076

[minleejae]

Hi, @manticore-projects

Could you please let me know when the JSqlParser 5.2 release is scheduled?
I'd like to reference this for planning purposes in my project.

Thanks!

[manticore-projects]

Could you please let me know when the JSqlParser 5.2 release is scheduled?

Unfortunately this is not on me, but I will ask @wumpz immediately and with some luck, he will get this done in May.
Would this work for you?

[manticore-projects]

Please fix formatting exceptions.

[minleejae]

@manticore-projects
Thanks for the reply!

I'm currently working on a project that depends on JSqlParser, and I'm considering switching to the official release version rather than using a custom build.
There's no urgency at all — I just wanted to get a rough idea of the possible timeline.
Appreciate your help, thank you!

[manticore-projects]

Thank you for your work and effort! Cheers!