Re: Possible MySQL Bug

[Jaft]

I didn't have much time to work on the PR this weekend, sadly, but I think I found three sites that lay out the possible commands for each one: https://www.postgresql.org/docs/10/sql-delete.html, https://dev.mysql.com/doc/refman/8.0/en/delete.html, and https://sqlite.org/lang_delete.html.

So the required elements for all three are the same (DELETE FROM <table>) while all three accept a WHERE statement.

All the differences seem to be in the optional keywords; so, if only implementing the required elements and adding another branch like ((row-delete) (apply row-delete tname args)) to the function gen-sql, row-delete could just be written as

(define (row-delete tname t)

  (->sql delete from table tname t))

But, to account for the optional keywords, t would need to be parsed since some of the keywords belong before the DELETE keyword while some go after the DELETE but before the FROM.

I mostly bring it up since there really aren't any examples I see to base it off of (I don't think); all the other ones seem to have pretty precise number of arguments they expect. I guess we could have row-delete take an args list for the last parameter and it could get parsed for particular keywords.

But I guess I just wanted to check how you'd prefer to handle that or how much of the optional elements of each command you wanted to be implemented, since I wasn't sure.

Jonathan

On Thursday, October 29, 2020, 1:55:32 AM CDT, Nala Ginrut <mulei@gnu.org> wrote:

Jaft writes:

>  Nala writes:
>> I think what you're looking for is make-table-modifier, however, the> delete operation is missing somehow, I may forgot to add it.
> Oh, cool; adding to an already existing make-table- function makes this a lot easier.
>> The modifications in mysql/postgresql/sqlite3 are different, so we have> to take care of them.
> They are? Granted, I haven't done a lot of extensive SQL but I thought they all followed the basic
>
> DELETE FROM <table_name>WHERE      <condition>;

I haven't checked the differences, but you may see what I've done for
other operation like alter/drop...etc. Usually, there's slightly
difference in SQL syntax. Although you may only focus on MySQL/MariaDB
for this PR, you may want to have a look around others.

>> The FPRM is still experimental and not well tested yet, but I encourage> you to report any exceptions.
> Funnily enough, – not directly in the fprm.scm file but used by it – I noticed in ssql.scm that both the last option for both sql-update and sql-delete call ->where with the WHERE portions being run through sql-where before being sent to ->where (lines 173 and 186).
> But ->where uses sql-where in both possible cases so you end up basically sending a string to sql-where in ->where. I think line 173 is supposed to be
>
> (->where end (sql-update table set pairs) rest ...)
>
> and line 186
>
> (->where end (sql-delete from table) rest ...)
>
> If I'm correct, would you want me to create a PR to correct those? Or just roll those fixes into the PR for deleting rows in FPRM?

I think you're right!
It's a bug, and I think you can create a PR for it.
I'm looking forward to our new contributor. ;-)

> Finally, should I fork from master and make the PR to there or use another branch? My assumption is master but just thought I should double check.

For this thread, I think there should be 2 independent PR.
And yes you can fork master branch.
For now, it's OK to use fork. If we have more contributors, I'd like to
use branch-based PR. Anyway, let's focus on fork-based PR right now.

Best regards.


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