How do I just select the "occupation"? - postgresql

Question

I have the following:
SELECT *
FROM (
SELECT '{"people": [{"name": "Bob", "occupation": "janitor"}, {"name": "Susan", "occupation": "CEO"}]}'::jsonb as data
) as b
WHERE data->'people' #> '[{"name":"Bob"}]'::jsonb;
I am filtering for the object '{"name": "Bob", "occupation": "janitor"}'
How do I return Bob's occupation ("janitor")?
SELECT data->'people'->>'occupation'
FROM (
SELECT '{"people": [{"name": "Bob", "occupation": "janitor"}, {"name": "Susan", "occupation": "CEO"}]}'::jsonb as data
) as b
WHERE data->'people' #> '[{"name":"Bob"}]'::jsonb;
returns
?column?
--------
NULL
Looking for:
occupation
----------
janitor

Answer 1

If you don't care about anything else on the row where the jsonb is, you can take all elements out of the jsonb and then use them as separate elements to select from
SELECT data->>'occupation' as occupation
FROM (
SELECT jsonb_array_elements(
'{"people":
[
{"name": "Bob", "occupation": "janitor"},
{"name": "Susan", "occupation": "CEO"}
]
}'::jsonb->'people') as data) as b
WHERE data #> '{"name":"Bob"}';
Results
occupation
-----------
janitor
(1 row)

Answer 2

Your "people" element is an array. You can get at the elements of an array with the jsonb_array_elements function. After that, you can just filter on person->>'name':
SELECT person->>'occupation' as occupation
FROM (
SELECT person.value as person
FROM (
SELECT
'{"people":
[
{"name": "Bob", "occupation": "janitor"},
{"name": "Susan", "occupation": "CEO"}
]
}'::jsonb as data
) a
CROSS JOIN
jsonb_array_elements(data->'people') as person
) b
WHERE person->>'name' = 'Bob';
Note that ->> returns text, while -> returns jsonb.