Is there a way to create a new element in an existing json object using jq? Example below:
Let's say I have this json object and would like to add a new element to foo:
json='{
"id": "<id>>",
"name": "<name>",
"properties": {
"State": "<state>",
"requests": [],
"foo": [
{
"id": "<id1>",
"bar1": [
{
"baz1": "*"
}
]
},
{
"id": "<id2>",
"bar2": [
{
"baz2": "*"
}
]
}
]
}
}'
This command works to do that:
json2=$($json1 | jq '.properties.foo += [ { "id": "<id3>", "bar3": [ { "baz3": "*"} ] } ]')
However, running that same command without a preexisting foo element fails (example array below):
json3='{
"id": "<id>>",
"name": "<name>",
"properties": {
"State": "<state>",
"requests": []
}
}'
Is there a way in jq to create that element in the json object if one already does not exist?
Thanks!
There is nothing wrong with your jq program, which can be seen by running:
jq '.properties.foo += [ { "id": "<id3>", "bar3": [ { "baz3": "*"} ] } ]' <<< "$json3"
It looks like the problem is with your invocation but since it's not clear what $json1 is, I'll just guess that the above is sufficient for you to resolve the issue.
Related
I have just started using jq and I need to check if a given json is present in another json using jq?
Suppose this is my json_input:
{
"info": {
"values": [
{
"data": [
{
"name": "name",
"value": "val"
}
]
}
]
}
}
I need to check if the above json input is present inside the following available_json:
{
"info": {
"values": [
{
"data": [
{
"name": "name",
"value": "val"
},
{
"name": "name2",
"value": "val2"
},
{
"name": "name3",
"value": "val3"
}
],
"key1":"val1",
"key2":"val2"
}
],
"priority":1,
"objects":[
{
"name":"a"}
]
}
}
Both json are stored in variables and should report the presence for any json_input given as input based on any available_json (generic). How can this be done using jq?
Or Is there any other better way like converting both json to string and then comparing?
PS: The json object key info is fixed and the values can change.
This is so trivial that one might not even think of it: Using the jq filter contains:
jq 'contains({
"info": {
"values": [
{
"data": [
{
"name": "name",
"value": "val"
}
]
}
]
}
})' available.json
Output will be true or false. If you run jq -e (--exit-status), it will set the exit status accordingly, which allows you to use it together with if or &&/|| in your shell.
If you the input_json is also stored in a file:
jq --slurpfile input_json input_json 'contains($input_json[0])' available.json
If the JSON document is stored in a variable, then --argjson instead of --slurpfile:
jq --argjson input_json "$input_json" 'contains($input_json)' available.json
or simply relying on parameter expansion of your shell:
jq "contains($input_json)" available.json
In case, I have an original json look like the following:
{
"taskDefinition": {
"containerDefinitions": [
{
"name": "web",
"image": "my-image",
"environment": [
{
"name": "DB_HOST",
"value": "localhost"
},
{
"name": "DB_USERNAME",
"value": "user"
}
]
}
]
}
}
And I would like to inplace modify the value for the matched key like so:
jq '.taskDefinition.containerDefinitions[0].environment[] | select(.name=="DB_USERNAME") | .value="new"' json
I got the output
{
"name": "DB_USERNAME",
"value": "new"
}
But I want more like in-place modify or the whole json from the original with new value modified, like this:
{
"taskDefinition": {
"containerDefinitions": [
{
"name": "web",
"image": "my-image",
"environment": [
{
"name": "DB_HOST",
"value": "localhost"
},
{
"name": "DB_USERNAME",
"value": "new"
}
]
}
]
}
}
Is it possible to do with jq or any known workaround?
Thank you.
Updated
For anyone looking for editing multi-values,
here is the approach I use
JQ=""
for e in DB_HOST=rds DB_USERNAME=xxx; do
k=${e%=*}
v=${e##*=}
JQ+="(.taskDefinition.containerDefinitions[0].environment[] | select(.name==\"$k\") | .value) |= \"$v\" | "
done
jq '${JQ%??}' json
I think there should be more concise way, but this seems working fine.
It is enough to assign to the path, if you are using |=, e.g.
jq '
(.taskDefinition.containerDefinitions[0].environment[] |
select(.name=="DB_USERNAME") | .value) |= "new"
' infile.json
Output:
{
"taskDefinition": {
"containerDefinitions": [
{
"name": "web",
"image": "my-image",
"environment": [
{
"name": "DB_HOST",
"value": "localhost"
},
{
"name": "DB_USERNAME",
"value": "new"
}
]
}
]
}
}
Here is a select-free solution using |=:
.taskDefinition.containerDefinitions[0].environment |=
map(if .name=="DB_USERNAME" then .value = "new"
else . end)
Avoiding select within the expression on the LHS of |= makes the solution more robust w.r.t. the version of jq being used.
You might like to consider this alternative to using |=:
walk( if type=="object" and .name=="DB_USERNAME"
then .value="new" else . end)
I have a json file like below. I want to add "stable": "yes" to every object in this file with jq. How can i do this?
[
{
"id":"1",
"name":"Blue"
},
{
"id":"2",
"name":"Red"
}
]
I want it to be like this:
[
{
"id":"1",
"name":"Blue",
"stable": "yes"
},
{
"id":"2",
"name":"Red",
"stable": "yes"
}
]
map and + will do this:
$ jq 'map(. + {stable: "yes"})' tmp.json
[
{
"id": "1",
"name": "Blue",
"stable": "yes"
},
{
"id": "2",
"name": "Red",
"stable": "yes"
}
]
Since the input is an array, the . refers to each object in that array, to which we add another object.
Note this will also override any existing stable key in each object.
I need to remove all array elements that have the name field ending with 1.
Input:
{
"foo": "bar",
"data": {
"code": "abc123",
"items": [
{
"name": "exp1"
},
{
"name": "exp2"
},
{
"name": "exp11"
}
]
}
}
Desired output:
{
"foo": "bar",
"data": {
"code": "abc123",
"items": [
{
"name": "exp2"
}
]
}
}
My attempt:
jq 'del(.data.items[] | select(.name | endswith("1")))' input
Which results in Invalid path expression.
You can use this jq filter:
jq '.data.items|=map(select(.name|endswith("1")|not))' file
This replace .data.items with the a new array having objects whose names don't end with 1.
Your attempt will work with recent versions of jq (that is, more recent than version 1.5).
Yet another variant (perhaps the most concise robust alternative):
.data.items|=map(select(.name|test("[^1]$")))
Hi I have the below JSON file with nested object:
{
"Maps": {
"Campus": [
{
"name": "nus",
"Building": [
{
"name": "sde1",
"Floor": [
{
"name": "floor1"
},
{
"name": "floor2"
}
]
},
{
"name": "sde2"
}
]
},
{
"name": "ntu",
"Building": [
{
"name": "ece1",
"Floor": [
{
"name": "floor1"
},
{
"name": "floor2"
}
]
},
{
"name": "ece2"
}
]
}
]
}
}
I want to use jq to parse the above JSON file and get the below format:
nus>sde1>floor1
nus>sde1>floor2
ntu>ece1>floor1
ntu>ece1>floor2
basically I have to concatenate the Campus Name with Building Name and Floor name and put a < symbol in between.
If the nested object field Floor is not exist, ignore the parse and continue the next child object.
How to achieve that? thanks.
You can use the following jq command:
jq '.Maps.Campus[]|"\(.name)>\(.Building[]|"\(.name)>\(.Floor[]?.name)")"' file.json
jq is smart enough to print the combinations of .name and .Building[].name since .Building is an array. The same action get's applied to .Building[].name and Floor[]?.name. ? because floor is not always set.
Here is a solution which uses jq variables
.Maps.Campus[]
| .name as $campus
| .Building[]
| .name as $bldg
| .Floor[]?
| .name as $floor
| "\($campus)>\($bldg)>\($floor)"