Select tool - handle missing fields with default value

[toral]

Hi,

I have an iterative macro that receives json response, parses the same into csv and then outputs the selected fields. 

The response payload is a bit dynamic in the sense it won't return all the fields always. Like: 

{
     "elements": [
     {
         "type": "abc",
         "currentStatus": "Pending",
         "id": "12345",
         "city": "Chicago",
         "country": "United States"
}]}

and sometimes: 

{
     "elements": [
     {
         "type": "abc",
         "currentStatus": "Pending",
         "id": "8765",
         "country": "United States"
}]}

City is missing in the second response.

The select tool does not identify a field such as City and the final output csv structure changes from 5 fields to just 4.

The select tool says missing fields when the city field is not available. 

What's the best way to handle this. 

I want the output to be all the 5 fields 

Attached a snapshot of the workflow: 

[toral · Accepted solution]

This was handled by adding a 0 record file (skeleton file) with the fields of interest. This skeleton merged with the select output gave the final consistent result as needed.