Get all paths of matching jsonpath filter - postgresql

Question

I'm using PostgreSQL 14.
I need to find all paths that matches the jsonpath filter I give.
Input example
{
"A": [
{
"B": [
[
{
"name": "id",
"conditions": [
{
"validator": "nonnull"
}
]
},
{
"name": "x",
"conditions": [
{
"validator": "required"
}
]
},
{
"name": "y",
"rules": []
}
],
[
{
"name": "z",
"conditions": [
{
"validator": "required"
}
]
}
]
]
}
]
}
JsonPath filter
Every A.B which has a required validator condition:
$.A.B[*].conditions ? (#.validator == "required")
Expected output (Or something close)
{A,0,B,0,1,conditions,0}
{A,0,B,1,0,conditions,0}

Answer 1

This is a relational solution, you may define the query as a view and filter on the validator and you get the array indexes.
select a.index-1 as a,
b.index-1 as b,
b2.index-1 as b2,
c.item ->> 'validator' as validator,
c.index-1 as conditions
from t cross join
jsonb_array_elements(jsn -> 'A') WITH ORDINALITY a(item, index) cross join
jsonb_array_elements(a.item -> 'B') WITH ORDINALITY b(item, index) cross join
jsonb_array_elements(b.item) WITH ORDINALITY b2(item, index) cross join
jsonb_array_elements(b2.item -> 'conditions') WITH ORDINALITY c(item, index);
a|b|b2|validator|conditions|
-+-+--+---------+----------+
0|0| 0|nonnull | 0|
0|0| 1|required | 0|
0|1| 0|required | 0|