how do i query with the AND keyword using the sql::selectfrom() function, all of the examples i found didn't include an AND keyword to the constraint expression

Are you developing an extension? If you're developing a table (in core) I would suggest against using the

SQL::

APIs, they are fairly expensive. Is there another way to get the data you want? But to answer your question I'd recommend using

SQL::SQL

with a query and then going from there.

yes i am developing an extension, and i am trying to grab the local ip of the machine, which is rather hard when not using the sql:: apis.

That makes sense. I don't have a good answer off the top of my head. I'd recommend investigating the implementation of

::selectAllFrom

or using the default

select * from interface_addresses

then applying some filtering logic in the extension code.

currently my query looks like this

core code api documentation

I agree. I think improving both the API and the documentation should be a prioritized goal for the next release. (could use help with it, as usual)