Find object by key/value in an array in postgresql jsonb column - json

Question

I have the following table:
CREATE TABLE api_data (
id bigserial NOT NULL PRIMARY KEY,
content JSONB NOT NULL
);
Now I insert an array like this into the content column:
[{ "id": 44, "name": "address One", "petId": 1234 },
{ "id": 45, "name": "address One", "petId": 1234 },
{ "id": 46, "name": "address One", "petId": 1111 }]
What I want next is to get exactly the objects that have the "petId" set to a given value.
I figured I could do
select val
from api_data
WHERE content #> '[{"petId":1234}]'
But that returns the whole array.
Another thing I found is this query:
select val
from api_data
JOIN LATERAL jsonb_array_elements(content) obj(val) ON obj.val->>'petId' = '1234'
WHERE content #> '[{"petId":1234}]'
Which returns the object I am looking for, but three times which matches the number of elements in the array.
What I actually need is a result like this:
[{ "id": 44, "name": "address One", "petId": 1234 },
{ "id": 45, "name": "address One", "petId": 1234 }]

Answer 1

If you are using Postgres 12, you can use a JSON path expression:
select jsonb_path_query_array(content, '$[*] ? (#.petId == 1234)') as content
from api_data
where content #> '[{"petId":1234}]';
If you are using an older version, you need to unnest and aggregate manually:
select (select jsonb_agg(e)
from jsonb_array_elements(d.content) as t(e)
where t.e #> '{"petId":1234}') as content
from api_data d
where d.content #> '[{"petId":1234}]'