Selecting from nested array

Question

Given this input

{
  "data": [
    {
      "id": "001",
      "metadata": {
        "item1": 1
      },
      "records": [
        {
          "name": "name1",
          "type": "type1"
        },
        {
          "name": "name2",
          "type": "type2"
        }
      ]
    },
    {
      "id": "002",
      "metadata": {
        "item1": 1
      },
      "records": [
        {
          "name": "name1",
          "type": "type1"
        }
      ]
    },
    {
      "id": "003",
      "metadata": {},   
      "records": [
        {
          "name": "name1",
          "type": "type1"
        },
        {
          "name": "name2",
          "type": "type2"
        }
      ]
    }
  ]
}

I am trying to output this

[
  {
    "id": "001",
    "Item1": 1,
    "Name": "name2"
  },
  {
    "id": "002",
    "Item1": 1,
    "Name": null
  },
  {
    "id": "003",
    "Item1": null,
    "Name": "name2"
  }
]

However using this

jq '[.data[] | {id, "Item1": .metadata.item1, "Name": .records[] | select(.type == "type2").name}]'

jq query I am getting this

[
  {
    "id": "001",
    "Item1": 1,
    "Name": "name2"
  },
  {
    "id": "003",
    "Item1": null,
    "Name": "name2"
  }
]

How can I get the '002' id object to output as well? I have tried various if then else conditions statements but to no avail.

Thor · Accepted Answer · 2017-04-18 11:47:13Z

1

I am quite new to jq so this is probably not an optimal solution.

If you map the select onto the records array instead, the surrounding object is not removed. For example:

parse.jq

[
  .data[] | 
  {
    id    : .id,
    Item1 : .metadata.item1,
    Name  : .records | map(select(.type == "type2"))[0].name
  }
]

Run it like this:

jq -f parse.jq file.json

Output:

[
  {
    "id": "001",
    "Item1": 1,
    "Name": "type2"
  },
  {
    "id": "002",
    "Item1": 1,
    "Name": null
  },
  {
    "id": "003",
    "Item1": null,
    "Name": "type2"
  }
]

answered Apr 18, 2017 at 11:47

Thor

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Comments

gaganshera · Accepted Answer · 2017-04-15 11:16:55Z

0

It can be because the 2nd nested array doesn't satisfy the condition

select(.type == "type2")

answered Apr 15, 2017 at 11:16

gaganshera

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1 Comment

user2631085 Over a year ago

I understand this but how can I have something that doesn't satisfy this condition yet still return something from the parent object metadata.

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