Bringing userdata into Lua without C (or how much C do I need to learn to do this)

Question

Hi and thanks in advance. I'm trying to see if there's a way to avoid learning C (which I don't know at all) to turn userdata into a Lua table.

I'm using an application which lets users write addons using Lua scripts. These addons can query the application's underlying data. However the query results are returned as userdata and I need them to be available back in the script.

I haven't been able to find anything in the applications documentation about working with returned datasets. The only description given is that the operation I'm running:

Executes the currently assigned query string and uses the results to construct either a DataSet object if multiple result sets are returned or a DataTable if one or no result sets are returned.

In my case I'll be getting multiple result sets, I'm referring to it as userdata because that's what I get when I call type() on the query result.

I've looked at the Lua documentation which seems like it could be useful but lacking any familiarity with C I have no idea what I'm looking at. The metatable tells me I have access to the __index, __newindex, __tostring, and __gc metamethods. Calling tostring gives me a seven-digit integer which is (I think) completely unrelated to my data. It's possible I'm not even getting the data I want back at all, but I can't figure a way to check that. Online resources either say this can't be done or provide solutions in C which are probably clever, clean, and awesome but I don't understand them.

So I'm looking for some more definitive guidance on whether I can/should do this, if there's a way to do this without C (or just by blindly copying someone else's code), or -- if I need to use C for this -- if we're talking about the 90 minute or the 7 hour Lynda Introduction to C course to get where I need to be?

(and apologies if I've inadvertently violated any community norms with this question...it's my first time posting)