flatten array of maps to create tsv format

[ckuenne]

i'm trying to collapse/flatten a structure so i can convert to tsv format.

Version of yq: 4.45.1
Operating system: Debian 11
Installed via: wget binary release

test.yml:

- name: Miller, Tim
  email: Tim.Miller@xy.com
  user_metadata:
    username: tmiller
    x: 1
- name: Jones, Karen
  email: Karen.Jones@z.com
  user_metadata:
    username: kjones
    y: 2

this works as long as i ignore the map "user_metadata":

yq -o tsv '.[] |= pick(["name","email"])' test.yml
->
name	email
Miller, Tim	Tim.Miller@xy.com
Jones, Karen	Karen.Jones@z.com

but i also need to flatten the map inside the array (basically remove the first level) and then select from the remaining keys. this is my desired output:

name	email	username
Miller, Tim	Tim.Miller@xy.com	tmiller
Jones, Karen	Karen.Jones@z.com	kjones

it's probably not difficult but i'm out of ideas...

[jandubois]

If you want just this specific operation and not a generic flattening, you can just pick the fields yourself instead of using pick:

❯ yq -o tsv '.[] |= {"name":.name, "email":.email, "username":.user_metadata.username}' test.yml
name	email	username
Miller, Tim	Tim.Miller@xy.com	tmiller
Jones, Karen	Karen.Jones@z.com	kjones

[jandubois]

This should be moved to "Discussions" as it is not a bug / feature request...

[ckuenne]

that solves my current use case already, thx a lot! new i just missed something basic.

but it would indeed be cool to have a more generic version that works with less hardcoding.