Is there a jsonb array overlap function for postgres? - arrays

Question

Am not able to extract and compare two arrays from jsonb in postgres to do an overlap check. Is there a working function for this?
Example in people_favorite_color table:
{
"person_id":1,
"favorite_colors":["red","orange","yellow"]
}
{
"person_id":2,
"favorite_colors":["yellow","green","blue"]
}
{
"person_id":3,
"favorite_colors":["black","white"]
}
Array overlap postgres tests:
select
p1.json_data->>'person_id',
p2.json_data->>'person_id',
p1.json_data->'favorite_colors' && p2.json_data->'favorite_colors'
from people_favorite_color p1 join people_favorite_color p2 on (1=1)
where p1.json_data->>'person_id' < p2.json_data->>'person_id'
Expected results:
p1.id;p2.id;likes_same_color
1;2;t
1;3;f
2;3;f
--edit--
Attempting to cast to text[] results in an error:
select
('{
"person_id":3,
"favorite_colors":["black","white"]
}'::jsonb->>'favorite_colors')::text[];
ERROR: malformed array literal: "["black", "white"]"
DETAIL: "[" must introduce explicitly-specified array dimensions.

Answer 1

Use array_agg() and jsonb_array_elements_text() to convert jsonb array to text array:
with the_data as (
select id, array_agg(color) colors
from (
select json_data->'person_id' id, color
from
people_favorite_color,
jsonb_array_elements_text(json_data->'favorite_colors') color
) sub
group by 1
)
select p1.id, p2.id, p1.colors && p2.colors like_same_colors
from the_data p1
join the_data p2 on p1.id < p2.id
order by 1, 2;
id | id | like_same_colors
----+----+------------------
1 | 2 | t
1 | 3 | f
2 | 3 | f
(3 rows)