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Aniket Satbhai
Aniket Satbhai

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Using jq to filter JSON data

#json #jq #filter #api

Basic Elements

  • .
    . - Same as input when used standalone,
    .key - Value of the key

  • []
    [] - Select array,
    [n] - Select nth element in the array,
    [.key1, .key2, ..] - Create new json object

  • {}
    {key1: .key1, key2: .key2, ..}
    or
    {key1, key2, ..} - Create new json object

n ∉ [0, ∞), int

Ex.

file.json

[ { "id": 1, "name": "test1" }, { "id": 2, "name": "test2" } ]
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To filter ids:

$ jq '.[].id' file.json 1 2 $ cat file.json | jq '.[] | .id' 1 2 $ cat file.json | jq '.[].id' 1 2
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To return value of name key when id is 1

$ jq '.[] | select(.id == 1) | .name' file.json "test1" $ cat file.json | jq '.[] | select(.id == 1) | .name' "test1"
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To filter ids as json

$ jq '.[] | {id}' file.json { "id": 1 } { "id": 2 } $ cat file.json | jq '.[] | {id}' { "id": 1 } { "id": 2 } $ cat file.json | jq '.[] | {id: .id}' { "id": 1 } { "id": 2 }
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Ref. :
https://stedolan.github.io/jq/
https://programminghistorian.org/en/lessons/json-and-jq

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