How to query nested array with heterogeneous elements in PostgreSQL JSONB column - json

Question

I have a JSONB field in PostgreSQL (12.5) table Data_Source with the data like that inside:
{
"C1": [
{
"id": 13371,
"class": "class_A1",
"inputs": {
"input_A1": 403096
},
"outputs": {
"output_A1": 403097
}
},
{
"id": 10200,
"class": "class_A2",
"inputs": {
"input_A2_1": 403096,
"input_A2_2": 403095
},
"outputs": {
"output_A2": [
[
403098,
{
"output_A2_1": 403101
},
{
"output_A2_2": [
403099,
403100
]
}
]
],
"output_A2_3": 403102,
"output_A2_4": 403103,
"output_A2_5": 403104
}
}
]
}
Could you please suggest me some SQL query to extract outputs from the JSONB field.
What I need to get as a results:
Output:
name
value
output_A1
403096
output_A2
403098
output_A2_1
403101
output_A2_2
403099
output_A2_2
403100
output_A2_3
403102
output_A2_4
403103
output_A2_5
403104
Any ideas?

Answer 1

Whenever an array is encountered, then JSONB_ARRAY_ELEMENTS(), or an object is encountered, then JSONB_EACH() functions might be applied, along with auxiliary JSONB_TYPEOF() function to determine respective types, consecutively. At the end, combine the results whether of type array or object or not through use of UNION ALL such as
WITH j AS
(
SELECT j2.*, JSONB_TYPEOF(j2.value) AS type
FROM t,
JSONB_EACH(jsdata) AS j0(k,v),
JSONB_ARRAY_ELEMENTS(v) AS j1,
JSONB_EACH((j1.value ->> 'outputs')::JSONB) AS j2
), jj AS
(
SELECT key,j1.*,JSONB_TYPEOF(j1.value::JSONB) AS type
FROM j,
JSONB_ARRAY_ELEMENTS(value) AS j0(v),
JSONB_ARRAY_ELEMENTS(v) AS j1
WHERE type = 'array'
), jjj AS
(
SELECT key,j0.v,JSONB_TYPEOF(j0.v::JSONB) AS type,k
FROM jj,
JSONB_EACH(value) AS j0(k,v)
WHERE type IN ('array','object')
)
SELECT key,value
FROM
(
SELECT key,value,type
FROM j
UNION ALL
SELECT key,value,type
FROM jj
UNION ALL
SELECT k,v,type
FROM jjj
) jt
WHERE type NOT IN ('array','object')
UNION ALL
SELECT k,value
FROM jjj,JSONB_ARRAY_ELEMENTS(v) AS j0
WHERE type IN ('array','object')
Demo