Fixes: #5696
Add missing MySQL keywords.
### Description
Adds some missing keywords from the MySQL dialect. While it's hard to describe this as a documentation/typographical fix, there are no current test for presence of the correct keywords, nor a realistic way to implement them those tests.
### Checklist
This pull request is:
- [x] A documentation / typographical error fix
- Good to go, no issue or tests are needed
- [ ] A short code fix
- please include the issue number, and create an issue if none exists, which
must include a complete example of the issue. one line code fixes without an
issue and demonstration will not be accepted.
- Please include: `Fixes: #<issue number>` in the commit message
- please include tests. one line code fixes without tests will not be accepted.
- [ ] A new feature implementation
- please include the issue number, and create an issue if none exists, which must
include a complete example of how the feature would look.
- Please include: `Fixes: #<issue number>` in the commit message
- please include tests.
Closes: #5567
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5567
Pull-request-sha:
db76e7f9d3a903cb4acf0309d57a14fe69948a0f
Change-Id: Ieaef45d0214fc9052a36924bfee38df9a27f7040