Understanding the notation (arr = [1.2], arr2=[5, 7])

I’m came across a notation in the LibPQ.jl documentation:

    (no_nulls = ["foo", "baz"], yes_nulls = ["bar", missing]),
    "INSERT INTO libpqjl_test (no_nulls, yes_nulls) VALUES (\$1, \$2);",

where (no_nulls = [“foo”, “baz”], yes_nulls = [“bar”, missing]) is used as an argument. Could you please explain what this notation means and how it works? I would have guessed it’s just a pair of two arrays, but looking into the LibPQ library (https://github.com/invenia/LibPQ.jl/blob/master/src/tables.jl) they call it a “table”, and I know there is something called Tables.jl (athough, I haven’t used it). Please help me understand. And how does it tie together to “$1” (which I can guess takes an elt from first array, but how does this really work)?