Flatten JSON data file - json

Question

I'm a JQ newb, and have been wrestling with this task for while.
Our source JSON file looks like this...
[
{
"id": "xxxx",
"title": "xxxx",
"created_at": "xxxx",
"updated_at": "xxxx",
"fields": [
{
"usernamevalue": "xxxx",
"reference": "xxxx"
},
{
"passwordvalue": "xxxx",
"reference": "xxxx"
},
{
"otherlabel": "xxxx",
"otherreference": "xxxx"
}
]
},
{
"id": "xxxx",
"title": "xxxx",
"created_at": "xxxx",
"updated_at": "xxxx",
"fields": [
{
"usernamevalue": "xxxx",
"reference": "xxxx"
},
{
"passwordvalue": "xxxx",
"reference": "xxxx"
},
{
"otherlabel": "xxxx",
"otherreference": "xxxx"
}
]
}
]
We are trying to end up with...
[
{
"title": "xxxx",
"updated_at": "xxxx",
"usernamevalue": "xxxx",
"passwordvalue": "xxxx"
},
{
"title": "xxxx",
"updated_at": "xxxx",
"usernamevalue": "xxxx",
"passwordvalue": "xxxx"
}
]
As such, the goals are...
End up with one, "flat" item for each entry -- so that we can then convert it to a CSV.
Only get the "title" and "updated_at" fields from the top level.
Only get fields with keys = "usernamevalue" and "passwordvalue" from the subordinate "fields" array, and move those fields to the top level.
Any guidance would be GREATLY appreciated!
(I've already spent more hours on this than I care to admit.)
THANK YOU

Answer 1

If usernamevalue and passwordvalue have only one occurrence as in your sample file, you can add the fields object, and then extract from it as you would with the outside keys:
jq 'map({id, updated_at} + (.fields | add | {usernamevalue, passwordvalue}))'
[
{
"id": "xxxx",
"updated_at": "xxxx",
"usernamevalue": "xxxx",
"passwordvalue": "xxxx"
},
{
"id": "xxxx",
"updated_at": "xxxx",
"usernamevalue": "xxxx",
"passwordvalue": "xxxx"
}
]
Demo
If your ultimate goal is a CSV output of the values, you'd rather go for an array than an object, which could be something like:
jq -r '.[] | [.id, .updated_at, (.fields | add | .usernamevalue, .passwordvalue)] | #csv'
"xxxx","xxxx","xxxx","xxxx"
"xxxx","xxxx","xxxx","xxxx"
Demo

Answer 2

You could parse the JSON object through their keys.
var jsonObject = [
{
"foo": "bar",
"foo1": "bar1",
"field": [
{
"username": "john#gm.com",
"context": "foob"
},
{
"password": "kek",
"context": "bar1"
},
{
"other": "foobar",
"context": "foobarbar"
}
]
}
]
for (var i = 0; i < jsonObject.field.length; i++)
{
for(var key in jsonObject.field[i])
{
if(key == "username")
{
jsonObject.usernamevalue = jsonObject.field[i].username;
} else if(key == "password")
{
jsonObject.passwordvalue = jsonObjecct.field[i].password;
}
}
}
//Afterwards, you can delete the field
delete jsonObject.field;