implement alter table for sqlite grammar

[miuy56dc]

implement alter table for SQLite grammar:https://www.sqlite.org/lang_altertable.html

[coveralls]

Pull Request Test Coverage Report for Build 137608205

• 62 of 66 (93.94%) changed or added relevant lines in 3 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.02%) to 91.821%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/parser.rs	28	29	96.55%
src/ast/ddl.rs	7	10	70.0%

Files with Coverage Reduction	New Missed Lines	%
src/ast/ddl.rs	1	85.0%

Totals
Change from base Build 134288244:	0.02%
Covered Lines:	4120
Relevant Lines:	4487

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💛 - Coveralls

[nickolay]

Hey @mz, thanks for the PR! Please let me know when this is ready for review, as I see you're still working on it.

[miuy56dc]

Hi @nickolay I'm working on the test coverage, I have already covered alter table test, but it still says that coverage decreased, can you help me to see what's wrong.

[nickolay]

The coverage is somewhat flaky unfortunately. Given that in this case it thinks that an existing line lost coverage, whereas it wasn't covered in the first place, I think it's not worth worrying about:

AlterTableOperation::DropConstraint { name } => write!(f, "DROP CONSTRAINT {}", name),

[miuy56dc]

The coverage is somewhat flaky unfortunately

Thanks, @nickolay , It's ready for review.

[mz]

Hey @mz, thanks for the PR! Please let me know when this is ready for review, as I see you're still working on it.

Hey, I'm @mz and he is @mashuai :-) but nice to meet you both anyway !

[nickolay]

Thanks! I added a couple of renames and merging this now.