get array from DB

As I do not get along in the other thread I ask the question here again:

1)
with the PHP action

return ["x2" => "x2", "y2" => "y2", "z2" => "z2"];

I get

Array
(
    [x2] => x2
    [y2] => y2
    [z2] => z2
)

That's the result I want, BUT with data from the DB

2)
when loading data from DB with the PHP action

return $this->get("read_data11.loadprices.prices_adult"); 

and the content of prices_adult = ["x2" => "x2", "y2" => "y2", "z2" => "z2"] I get a different result.
I get:

Array
(
    [0] => ["x1" => "x1", "y1" => "y1", "z1" => "z1"]
)

That is NOT what I want.

My question:
how do I have to modify the PHP action return $this->get("read_data11.loadprices.prices_adult") that I get the same result like in example 1)

I really hope to get this solved.