Add date function to get current date without time component

[paulrutter]

• Add CURDATE/CURRENT_DATE method to AlaSQL
• Add test

This removed the need for:

DATE(YEAR(NOW()) + '-' + MONTH(NOW()) + '-' + DAY(NOW()))

Thank you for the time you are putting into AlaSQL!

[paulrutter]

@mathiasrw any feedback on this pr? Thanks!

[mathiasrw]

Interesting, relevant and missing. Nice.

SELECT CURDATE();

looks good to me. I do feel like we should avoid none standard notation like SELECT CURRENT_DATE(); and instead support the widely use same notation as MySQL and MariaDB with SELECT CURRENT_DATE; where its not a function, but a constant.

Are you feeling the mojo to try to dive into that? Adding it to src/alasqlparser.jison should not be too complex, but I admit its a bit exotic if you have not worked with parsers before.

[paulrutter]

Isn't the function exactly what MySQL offers?
See https://www.w3schools.com/sql/func_mysql_curdate.asp and https://www.w3schools.com/sql/func_mysql_current_date.asp and https://www.techonthenet.com/mariadb/functions/current_date.php#:~:text=The%20CURRENT_DATE%20function%20will%20return,synonym%20for%20the%20CURDATE%20function.

I do see that most also support an alias as constant, although we don't offer this for other date functions except CURRENT_TIMESTAMP in alasql. The current approach would be in line with other AlaSQL date functions. Do you want me to look into using these aliases?

To the parser point, i'm not seeing the other date functions in there. Is that deliberate? Only CURRENT_TIMESTAMP is there, not NOW for example.

I can look into adding it to the parser though next week.

[paulrutter]

@mathiasrw I tried rebuilding the parser via npm run jison. but the resulting alasqlparser.js is completely different from what's in git right now. Should i use a different command?

I wouldn't expect changes against what's in git.
Also, when i run the tests after generating the parser again, a lot of tests fail due to the parser throwing errors.

I found #1903 (comment), will try that and update the package.json if that works.

[paulrutter]

@mathiasrw
Can you take a look at the changes made?
I also added a section to rebuild the parser and added both CURDATE as CURRENT_DATE.
It can be used with and without parenthesis.

It feels to me like other date functions should be added to the parser as well, as these are currently missing.
DATE/NOW/GETDATE/YEAR/MONTH for example.

[paulrutter]

#1936

[paulrutter]

Thanks for merging, can we expect a new release soon?
@mathiasrw

[mathiasrw]

Released as part of v4.5.0