Expanding a JSON array embedded in an object in Postgres 11.7 - sql

Question

Postgres 11.7. An upgrade to PG 12 (JSONPath, I know) is in planning stages, not sure when we'll get there.
I'm working on passing some data to a PL/PgSQL stored function, and am struggling to unpack an array embedded in an object. I'm dealing with some client libraries that Really Like Object as JSON Root. {[]} instead of [].
As a starting point, here's a sample that works when I get the array as the top-level element:
-- Note: jsonb instead of json may save reparsing time, if the results are reused.
-- Or so I think I heard.
with expanded_data AS (
select *
from jsonb_to_recordset(
'[
{"base_text":"Red Large Special","base_id":1},
{"base_text":"Blue Small","base_id":5},
{"base_text":"Green Medium Special","base_id":87}
]')
AS unpacked (base_text citext, base_id citext)
)
select base_text,
base_id
from expanded_data
This returns the hoped-for results:
base_text base_id
Red Large Special 1
Blue Small 5
Green Medium Special 87
This variant also works fine on a top-level array
with expanded_data AS (
select *
from json_populate_recordset(
null::record,
'[
{"base_text":"Red Large Special","base_id":1},
{"base_text":"Blue Small","base_id":5},
{"base_text":"Green Medium Special","base_id":87}
]')
AS unpacked (base_text citext, base_id citext)
)
select base_text,
base_id
from expanded_data
What I've failed to figure out is how to get these same results when the JSON array is embedded as an element within a JSON object:
{"base_strings":[
{"base_text":"Red Large Special","base_id":1},
{"base_text":"Blue Small","base_id":5},
{"base_text":"Green Medium Special","base_id":87}
]}
I've been working with the docs on the extraction syntax, and the various available functions...and haven't sorted it out. Can someone suggest a sensible strategy for expanding the embedded array elements into a rowset?

Answer 1

It is simple:
with expanded_data AS (
select *
from jsonb_to_recordset(
'{"base_strings":[
{"base_text":"Red Large Special","base_id":1},
{"base_text":"Blue Small","base_id":5},
{"base_text":"Green Medium Special","base_id":87}
]}'::jsonb -> 'base_strings') -- Chages here
AS unpacked (base_text citext, base_id citext)
)
select base_text,
base_id
from expanded_data;