Redshift can't cast text to boolean from json field

Question

In a Redshift database, given a field containing the following json:

{"0":true,"1":true,"2":true,"3":true,"4":true,"5":true,"6":true}

Although I can extract true using json_extract_path_text(my_field, '0') , when I'm trying to extract an element and cast it to a boolean as follow:

SELECT 
    json_extract_path_text(my_field, '0')::boolean
FROM my_table

I then get the following error:

cannot cast type text to boolean

I do not understand as the following is working without any issue:

SELECT 'true'::boolean, 'false'::boolean;

Answer 1

This post seems to answer the problem: https://stackoverflow.com/a/45799072

SELECT BOOLIN(TEXTOUT(json_extract_path_text('{"0":true}', '0')));