How to get particular object from jsonb in PostgreSQL?

I have a table called ‘Test’ that holds two fields ‘qnId’ and ‘Answers’. ‘qnId’ stores a uuid and ‘Answers’ is a jsonb array that roughly looks like this:

[{ "user" : "1", "ans" : "some text" }, { "user" : "3", "ans": "some text"}]

how can I retrieve the value of "ans" of "user" with value 3. How can I retrieve the value using normal SQL queries

Answer

demo:db<>fiddle

You can use jsonb_array_elements() to expand the array elements into one row each. Afterwards you are able to filter the right elements using the ->> operator (documentation):

SELECT
    uuid,
    elements ->> 'ans'
FROM
    mytable,
    jsonb_array_elements(answers) elements
WHERE 
    elements ->> 'user' = '3'