Using jq how can I replace the name of a key with something else

Question

This should be easy enough... I want to rename a few keys (ideally with jq), whatever I do seems to error though. Here is a json example below:

[
 {
  "fruit": "strawberry",
  "veg": "apple",
  "worker": "gardener"
 }
]

I'd like to rename the veg key to fruit2 (or example, whatever is easiest) and also the worker key to job.

I realize this is possible in sed, but I'm trying to get to grips with jq

RomanPerekhrest · Accepted Answer · 2019-03-27T20:49:24.983

48

Use the following jq approach:

jq '[.[] | .["fruit2"] = .veg | .["job"] = .worker | del(.veg, .worker)]' file

The output:

[
  {
    "fruit": "strawberry",
    "fruit2": "apple",
    "job": "gardener"
  }
]

edited Mar 27 '19 at 20:49

answered Apr 20 '17 at 14:41

RomanPerekhrest

88,541
4
65
105

6

Or use map instead, `jq 'map(.fruit2 = .veg | .job = .worker | del(.veg, .worker))' file` – Shawyeok Aug 27 '21 at 15:08
How would I do the same thing but in an object? – piegames Dec 26 '21 at 23:02

peak · Answer 2 · 2023-05-04T07:02:02.943

32

The key (:-) is with_entries. E.g., given a single object:

with_entries(if .key == "veg" then .key = "fruit2" else . end)

In your case, since you have an array of objects, you could wrap the above in map( ... ).

Note that if the original JSON object already has a key named "fruit2", then the usual "last-most wins" rule applies, where in this case, "last-most" refers to the array of key-value pairs that is used to determine the final result (as per the def of with_entries).

edited May 04 '23 at 07:02

answered Apr 20 '17 at 14:37

peak

105,803
17
152
177

this one is great ! How do you do with multiple keys ? – Varun Chandak Jun 03 '20 at 08:22
3

One way is to extend the argument to with_entries, e.g. with_entries( if .... end | if ... end) – peak Jun 03 '20 at 08:51
Notice: use target original value while target fields already exists. eg: `echo '{"veg":[1,2,3], "fruit2":["hello"]}' | jq 'with_entries(if .key == "veg" then .key = "fruit2" else . end)'` result: `{ "fruit2": [ "hello" ] }` – eaglewu May 04 '23 at 06:18

score 0 · Answer 3 · answered Mar 01 '23 at 00:16

For anyone looking to manipulate the key with a value from value:

$ echo '{ "foo": {"id": 123}, "bar": {"id":456} }'  | jq 'to_entries | map({key:(.key + "-" +(.value.id|tostring)), value:.value}) | from_entries'

If there is a shorter way to do it (maybe using with_entries), I would be happy to know.

score 0 · Answer 4 · answered Jul 14 '23 at 21:37

Here's how to use if-then-else-end with elif to rename multiple keys:

map(with_entries(.key |=
  if . == "fruit"  then "fruit2"
elif . == "worker" then "job"
else . end))

^{(jqplay example)}

Note in the current development branch / upcoming 1.7 release the empty else branch will be optional and could be removed, but it's still required in v1.6.

mohRamadan · Answer 5 · 2023-08-02T18:12:35.807

0

jq '[.[] | { fruit2: .veg, other_key: .other_orig_key }]'

check this example

edited Aug 02 '23 at 18:12

answered Aug 02 '23 at 17:53

mohRamadan

571
6
15

Using jq how can I replace the name of a key with something else

5 Answers5

Linked

Related