Json Path To extract array element with child Filter

Question

Hi I am looking to construct a jsonpath expression to find the array element that matches the filter on a child.

Please find details below

Json

{
  "items": [
    {
      "id": 1,
      "children": [
        {"id": 101, "name": "Child1"},
        {"id": 102, "name": "Child2"}
      ]
    },
    {
      "id": 2,
      "children": [
        {"id": 201, "name": "Child3"},
        {"id": 202, "name": "Child4"}
      ]
    }
  ]
}

Expected Result

[
  {
    "id": 2,
    "children": [
      {"id": 201, "name": "Child3"},
      {"id": 202, "name": "Child4"}
    ]
  }
]

I want to find the parent element which has the children with id=201

Please find the expression I have tried with respective results.

**Expression 1: **

$.items[?(@.children[?(@.id == 201)])]

Result:

[{"id":1,"children":[{"id":101,"name":"Child1"},{"id":102,"name":"Child2"}]},{"id":2,"children":[{"id":201,"name":"Child3"},{"id":202,"name":"Child4"}]}]

$.items[?(@.children[*].id == 201)]

Result: []

Note: I am using Jayway Library and have tried the solutions by chatgpt

Any Help would be appreciated .

Thanks in Advance

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Answer 1

I don't think that Jayway supports nested queries like your first attempt.

Note that it does work on my playground, https://json-everything.net/json-path. Mine implements the upcoming IETF specification in .Net.

You might be able to find another library that will work for youon the comparison site.

Answer 2

Using JsonPath-Plus This query on the origninal dataset:

items[*].children[?(@.id==201)]^^

will produce

[
  { "id": 2, "children": 
    [ 
      { "id": 201, "name": "Child3" },
      { "id": 202, "name": "Child4" } 
    ]
  }
]

$.items[*].children[?(@.id==201)]^^ produces the same result.

The JSONPath Demo site allows you to put in a dataset, a filter/query and see the results. Above, the query is:

1. Getting all the items
2. filtering the children by the ID==201
3. Getting the parent with the '^' operator. This goes up two generations in order to get the shape of the data that you wanted.