sql - JSON database table query

Question

I have JSON table with some objects and I am trying to query the amount value in the object

{
"authorizations": [
{
  "id": "d50",
  "type": "passed",
  "amount": 100,
  "fortId": 5050,
  "status": "GENERATED",
  "voided": false,
  "cardNumber": 3973,
  "expireDate": null,
  "description": "Success",
  "customerCode": "858585",
  "paymentMethod": "cash",
  "changeDatetime": null,
  "createDatetime": 000000000,
  "reservationCode": "202020DD",
  "authorizationCode": "D8787"
},
{
  "id": "d50",
  "type": "passed",
  "amount": 100,
  "fortId": 5050,
  "status": "GENERATED",
  "voided": false,
  "cardNumber": 3973,
  "expireDate": null,
  "description": "Success",
  "customerCode": "858585",
  "paymentMethod": "cash",
  "changeDatetime": null,
  "createDatetime": 000000000,
  "reservationCode": "202020DD",
  "authorizationCode": "D8787"
 }
 ],
 }

I have tried the following four options, but none of these give me the value of the object:

SELECT info @> 'authorizations:[{amount}]'
FROM idv.reservations;

SELECT info -> 'authorizations:[{amount}]'
FROM idv.reservations;

info -> ''authorizations' ->> 'amount'
FROM idv.reservations

select (json_array_elements(info->'authorizations')->'amount')::int from idv.reservations

note I am using DBeaver

Answer 1

If you want one row per object contained in the "authorizations" JSON array, with the corresponding amount, you can use a lateral join and jsonb_array_elements():

select r.*, (x.obj ->> 'amount')::int as amount
from reservations r
cross join lateral jsonb_array_elements(r.info -> 'authorizations') x(obj)

We can also extract all amounts at once and put them in an array, like so:

select r.*, 
    jsonb_path_query_array(r.info, '$.authorizations[*].amount') as amounts
from reservations r

Demo on DB Fiddlde