Forum Discussion

kiko's avatar
kiko
New Contributor
6 years ago
Solved

How can we combine two fields without explicitly referencing them?

Hello, we are trying to combine pairs of fields, without knowing their names in advanced. INPUT { "field1": "val1", "field2": "val2" } OUTPUT { "field12": "val1_val2" } The outp...
expression_language
transform
  • alchemiz's avatar
    alchemiz
    6 years ago

    Hi Kiko,

    I did use the _ from the key name to filter it out…

    here’s the expression:

    $input.mapValues((v,k)=> !(k).contains('_') ? $input.filter((i,j)=> j.startsWith(k)).values().join('_') : null).filter((v,k)=> !(v instanceof Null))

kiko's avatar
kiko
New Contributor
6 years ago

Hello, many thanks for your input. The challenge I am facing is that I can’t directly reference the target path. I will have input pairs of fields that I will need to merge and all they have in common will be the starting part of the key. Let me provide another example:

INPUT
{ "name": "val1", "name_b": "val2", "surname": "val3", "surname_b": "val4" }

OUTPUT
{ "name": "val1_val2", "surname": "val3_val4"}

I am flexible to generate a new key or updating an existing one, but I can’t refer to them in the target path because in every execution the input fields will be different.

Thanks again

alchemiz's avatar
alchemiz
Contributor III
6 years ago

Hi Kiko,

I did use the _ from the key name to filter it out…

here’s the expression:

$input.mapValues((v,k)=> !(k).contains('_') ? $input.filter((i,j)=> j.startsWith(k)).values().join('_') : null).filter((v,k)=> !(v instanceof Null))