Can we add custom translations ?

[moodymudskipper]

In sql_substr() we have an example showing us how to add a new variant.

I think I understand the general mechanism, sql_variant() receives "translators" which are environments containing functions creating strings of class "sql". I see also that sql_translator() has a .parent arg so we can inherit from a higher level translator.

But I don't quite understand how to idiomatically add a new translation to an existing variant.

A hack that I think will work OK for my project is to edit the base_odbc_scalar, base_odbc_agg, and base_odbc_win environments directly since they're exported and not locked, another would be to overwrite dbplyr:::sql_translation.Oracle (Since that's Oracle in my case) but seems a bit clunky as well.

I thought about using a super class of my "Oracle" too but it seems I'd have to set new methods for at least tbl() and probably more, that seems like a rabbit hole.

My use case FWIW is to add a series of functions such as count_if(), which don't exist in neither R or Oracle, I'd like also to implement some translations from str_replace to REGEXP_EXTRACT, the general idea is that I'd like this code to work the same before or after collecting.

Can you recommend a way to go at this ?

[moodymudskipper]

Might be a duplicate of #247

[hadley]

Duplicate of #309. Still don't have any good model for how we should implement this 😞