jq select() and sort_by()

Question

I am parsing a curl output from gitlab api, and I need to add a sort_by to my query, then select only certain values.

sample input:

[
  {
    "id": 10,
    "name": "another-test",
    "path": "another-test",
    "description": "",
    "visibility": "private",
    "lfs_enabled": true,
    "avatar_url": null,
    "web_url": "https://mygitlab/groups/another-test",
    "request_access_enabled": false,
    "full_name": "another-test",
    "full_path": "another-test",
    "parent_id": 9
  },
  {
    "id": 11,
    "name": "asdfg",
    "path": "asdfg",
    "description": "",
    "visibility": "private",
    "lfs_enabled": true,
    "avatar_url": null,
    "web_url": "https://mygitlab/groups/asdfg",
    "request_access_enabled": false,
    "full_name": "asdfg",
    "full_path": "asdfg",
    "parent_id": 7
  }

I parse the JSON with jq as follows:

curl http://..... | jq -r '.[] | select(.parent_id!=null) | .name, .parent_id' 

This works exactly as expected, but when I try to sort the results by parent_id, I get an error:

curl http://..... | jq -r '.[] | select(.parent_id!=null) | .name, .parent_id | sort_by(.parent_id)'
jq: error (at <stdin>:0): Cannot index number with string "parent_id"

I can use sort_by(), by putting a single dot instead than .[]:

curl http://..... | jq '. | sort_by(.parent_id) '

But I cannot combine the 2 functions.

Clarification: I need to extract name and parent_id, sorted by parent_id, when it is not null.

Thanks in advance

Answer 1

jq's sort_by() function accepts an array as input.

curl 'http://...' |
    jq -r '
        map(select(.parent_id != null)) 
        | sort_by(.parent_id)[]
        | [.name, .parent_id]
        | @tsv
    '

Sample output:

asdfg   7
another-test    9