Convert JSON array to PG array type and use it as generated column.

Readme.md

To convert a JSON array to be used as generated text[] column follow the steps below:

Define the following (immutable) function:

create or replace function json_array_to_pg_array(jsonarray jsonb) returns text[]
	as $$
		begin
			return (select array(select jsonb_array_elements_text(jsonarray)));
		end;
	$$ language plpgsql
	immutable
	returns null on null input

Then define your generated column by using the following snippet:

alter table <TABLENAME> add <GEN_COLUMN_NAME> text[] generated always as (
	json_array_to_pg_array(data#>'{<JSONPATH>}')
) stored