k0pernikus k0pernikus - 5 months ago 75
JSON Question

How to filter array of objects by element property values using jq?

I like to filter json files using jq:

jq . some.json


Given the json containing an array of objects:

{
"theList": [
{
"id": 1,
"name": "Horst"
},
{
"id": 2,
"name": "Fritz"
},
{
"id": 3,
"name": "Walter"
},
{
"id": 4,
"name": "Gerhart"
},
{
"id": 5,
"name": "Harmut"
}
]
}


I want to filter that list to only show the elements with id having the value 2 and 4, so the expected output is:

{
"id": 2,
"name": "Fritz"
},
{
"id": 4,
"name": "Gerhart"
}


How do I filter the json using jq? I have played around with select and map, yet didn't got any of those to work, e.g.:

$ jq '.theList[] | select(.id == 2) or select(.id == 4)' array.json
true

Answer

From the docs:

jq '.[] | select(.id == "second")' 

Input [{"id": "first", "val": 1}, {"id": "second", "val": 2}]

Output {"id": "second", "val": 2}

I think you can do something like this:

jq '.theList[] | select(.id == 2 or .id == 4)' array.json