Add support for executable SQL

[cyrusae]

Description

(Apologies if this has already been discussed--I didn't see anything matching it exactly.)

I've gotten a lot of use out of executable SQL blocks in R Notebooks for interactive ETL wrangling and was surprised that SQL wasn't an option in the code block creation dropdown in Quarto within Positron the same way. Is that feature in the works?

[mcanouil]

The dropdown provided by the IDE (extension for VSCode/Positron: https://github.com/quarto-dev/quarto or RStudio) is based on the engine main language. For example sql execution is only supported by engine: knitr and not with engine: jupyter or engine: julia. The IDE cannot show all supported languages from an engine/kernel, in the case of knitr, this would be a really bad UI/UX idea anyway as there are ore than 50 valid languages.

That's the main limitation as the IDE is static, providing "SQL" for Jupyter engine does not make sense.
The other limitation for interactive use is how to execute the code itself, this require a lot more logic than just letting knitr (or any other engines/kernels) handle the SQL and return the output.

Note that the feature has already been requested in the relevant repository:

• sql code cells feature quarto#26