JQ filter formatting - bash

Question

I have a JSON file I'd like to filter by the ID field, and show the matching Body and Source fields.
Format of the JSON file to filter
[
{
"timestamp" : 1638550971085,
"id" : "54f",
"body" : "Orange",
"source" : "827261"
},
{
"timestamp" : 1638550971096,
"id" : "54f",
"body" : "Apple",
"source" : "137261"
},
{
"timestamp" : 1638550971126,
"id" : "5da",
"body" : "Pear",
"source" : "1da61"
}
]
In this example I would like to filter where id = 54f and show the Timestamp (Unixtime converted to local time), Body and Source fields that match, ideally as shown below.
[Timestamp] Orange 827261
[Timestamp] Apple 137261
I have tried this command, but it is showing extra body / source fields outside of the SQL filter. It also adds a line break between printing the body and source, and ideally I'd like this printed on one line (tab separated). I also don't know how to convert the timestamp to localtime string.
more file.json | jq '.[] | select(.Id=="54f").body, .source'

Answer 1

Your JSON input is not proper JSON as it has
commas after the .source field but no following field
no commas between the elements of the top-level array
no quotes around the objects' field names
You'd need to address these issues first before proceeding. This is how it should look like:
[
{
"timestamp": 1638550971085,
"id": "54f",
"body": "Orange",
"source": "827261"
},
{
"timestamp": 1638550971096,
"id": "54f",
"body": "Apple",
"source": "137261"
},
{
"timestamp": 1638550971126,
"id": "5da",
"body": "Pear",
"source": "1da61"
}
]
Then you can go with this
localtime (available since jq 1.6) converts a timestamp of seconds (so, divide yours by 1000) since the Unix epoch into a so-called "broken down time" object (see the manual) which you can either process using strftime (see the answer from David Conrad), or parse yourself manually. With .[:3] | .[1] += 1 | join("-") I provided a rather primitive example for demonstration purposes which concatenates its first three items (year, month, day) with dashes in between, after incrementing the second item (as the month has a 0-based encoding) - for padding with zeroes check out one of the answers over here
#tsv creates tabs between the columns
jq -r '
.[]
| select(.id == "54f")
| [(.timestamp / 1000 | localtime | .[:3] | join("-")), .body, .source]
| #tsv
' file.json
2021-12-3 Orange 827261
2021-12-3 Apple 137261
Demo

Answer 2

As the other answer states, your JSON is not correct. After fixing that, you can filter and extract the data as that answer suggests, but use the strftime function to format the dates properly:
jq -r '.[] | select(.id == "54f")
| [(.timestamp / 1000 | localtime | strftime("%Y-%m-%d")), .body, .source]
| #tsv' file.json
The use of strftime("%Y-%m-%d") is critical to both displaying the correct month and formatting the date with leading zeroes on single-digit months and days.
2021-12-03 Orange 827261
2021-12-03 Apple 137261