Implement DATE_FORMAT function

[didendron]

Implement DATE_FORMAT according to the MySQL spec: https://dev.mysql.com/doc/refman/8.0/en/date-and-time-functions.html#function_date-format Tested against the actual output from MySQL using randomized inputs Documentation Integration tests

Relates to https://github.com/elastic/elasticsearch/issues/55065

[cla-checker-service[bot]]

💚 CLA has been signed

[didendron]

@cla-bot check

[elasticmachine]

Pinging @elastic/es-ql (Team:QL)

[luigidellaquila]

@elasticmachine test this please

[luigidellaquila]

Hi @didendron

Thank you very much for the quick feedback on my comments. I ran the tests locally and I see ConsistentFunctionArgHandlingIT is still failing. I think adding the function name to ConsistentFunctionArgHandlingIT-non-tested-functions.txt should be enough to fix it.

After that, could you please run the tests again and see if something else is missing?

Thanks

Luigi

[luigidellaquila]

@elasticmachine test this please

[luigidellaquila]

Hi @didendron

Thank you very much, this looks good for me now. Please, just align the PR with main branch (ie. merge main branch) so that I can run some final tests.

Thanks!

[luigidellaquila]

@elasticmachine test this please

[luigidellaquila]

Hi @didendron

Thank you very much for following up on this, I think we are almost there. If you could just address last comment from @astefan, I'd go on and merge

Thanks

Luigi

[didendron]

@Luegg, @astefan, and @luigidellaquila in particular thank you for your help and support.

[astefan]

Hi @didendron, Please, align the PR with main branch (ie. merge main branch) so that we can run the tests one more time with your new updates. Thanks.

[astefan]

@elasticmachine test this please

[astefan]

@elasticmachine run elasticsearch-ci/docs

[luigidellaquila]

Thank you very much @didendron, I'm merging the PR