Conditionally add a field in JSON transformation using JQ - json

Question

I am trying to transform my JSON to different structure using JQ. I am able to achieve my new structure, however i am getting feilds with Null objects if they are not present in Source, my client wants to remove the fields if they are having null values..
As i iterate i am able to get the structure in new format. But additional structures are coming.
Code Snippet- https://jqplay.org/s/w2N_Ozg9Ag
JSON
{
"amazon": {
"activeitem": 2,
"createdDate": "2019-01-15T17:36:31.588Z",
"lastModifiedDate": "2019-01-15T17:36:31.588Z",
"user": "net",
"userType": "new",
"items": [
{
"id": 1,
"name": "harry potter",
"state": "sold",
"type": {
"branded": false,
"description": "artwork",
"contentLevel": "season"
}
},
{
"id": 2,
"name": "adidas shoes",
"state": null ,
"type": {
"branded": false,
"description": "Spprts",
"contentLevel": "season"
}
},
{
"id": 3,
"name": "watch",
"type": {
"branded": false,
"description": "walking",
"contentLevel": "special"
}
},
{
"id": 4,
"name": "adidas shoes",
"state": "in inventory",
"type": {
"branded": false,
"description": "running",
"contentLevel": "winter"
}
}
],
"product": {
"id": 4,
"name": "adidas shoes",
"source": "dealer",
"destination": "resident"
}
}
}
JQ Query:
.amazon | { userType: .userType, userName: .user, itemCatalog: (.items | map({ itemId: .id, name, state} )) }
Expected Response:
{
"userType": "new",
"userName": "net",
"itemCatalog": [
{
"itemId": 1,
"name": "harry potter",
"state": "sold"
},
{
"itemId": 2,
"name": "adidas shoes"
},
{
"itemId": 3,
"name": "watch"
},
{
"itemId": 4,
"name": "adidas shoes",
"state": "in inventory"
}
]
}
With the query i have, i am getting state : null for the entries which has empty or null values. I want to hide the field itself in these cases.

Answer 1

Horrible solution, delete them after the query. There must be a neater way? (I started using jq today)
.amazon | { userType: .userType, userName: .user, itemCatalog: (.items | map({ itemId: .id, name, state} )) }| del(.itemCatalog[].state |select(. == null))
https://jqplay.org/s/jlNYmJNi25