evaluate jsonpath expression for the example

Question

{
  "a": [
    {
      "b": {
        "c": [
          {
            "id": "123"
          }
        ],
        "d": {
          "e": {
            "f": [
              {
                "name": "abc",
                "type": "in"
              },
              {
                "name": "xyz",
                "type": "out"
              }
            ]
          }
        }
      }
    },
    {
      "b": {
        "c": [
          {
            "id": "456"
          }
        ],
        "d": {
          "e": {
            "f": [
              {
                "name": "def",
                "type": "out"
              },
              {
                "name": "pqr",
                "type": "out"
              }
            ]
          }
        }
      }
    }
  ]
}

I am trying to extract the id's for which type='in'. So, as per the above example , the output should be 123 as only abc in the first element has the type 'in'. I tried multiple ways but not succeeded to extract it. Can someone please help on this?

With the following expression I am able to extract the node whose value is 'in' but how to extract the corresponding id/id's of the same object (i.e. 123)?

$.a[*].b.d[*].f[?(@.type=='in')]

Can try the json path here : JSON path online tool

UPDATE :

As per the suggestion from gregsdennis , I tried with the following by converting the IETF Json path mentioned to equivalent Jayway Json path which is not working :

$.a[?(@.b.d.e.f[?(@.type=='in')])].b.c[*].id

syntax error : jsonPath:

Unexpected token '?': _$_v.b.d.e.f[?(_$_v.type=='in'

Answer 1

You want

$.a[?@.b.d.e.f[?@.type == 'in']].b.c.*.id

NOTE: .* and [*] are equivalent.

This will search for all elements in $.a which contain a @.b.d.e.f which contains @.type == 'in', then it queries the result of that to get .b.c.*.id

The key is using nested queries.

• The outer query @.b.d.e.f[?@.type == 'in'] acts on the elements of a and is an existence test: it doesn't have any comparisons. If the test returns a non-empty result, then the element is selected.
• The inner query @.type == 'in' acts on the elements of f and checks for the condition that you want.

The final piece is simply navigating to the information you want (.b.c.*.id) from the elements of a that are returned.

---

This is compliant with the pending IETF JSON Path specification, which can be tested in my playground https://json-everything.net/json-path.

Not all libraries will be compliant with the specification. You'll need to check with the library you're using to see what's supported.