unable to parse json into csv using jq - bash

Question

I have a JSON file that I want to convert into a CSV file using the jq in a shell script. I want to create a single row from this entire JSON file. I have to extract value from values. The row output should be something like
null,642,642,412,0,null,null
Here is my JSON file
{
"data": [
{
"name": "exits",
"period": "lifetime",
"values": [
{
"value": {}
}
],
"title": "Exits",
"description": "Number of times someone exited the carousel"
},
{
"name": "impressions",
"period": "lifetime",
"values": [
{
"value": 642
}
],
"title": "Impressions",
"description": "Total number of times the media object has been seen"
},
{
"name": "reach",
"period": "lifetime",
"values": [
{
"value": 412
}
],
"title": "Reach",
"description": "Total number of unique accounts that have seen the media object"
},
{
"name": "replies",
"period": "lifetime",
"values": [
{
"value": 0
}
],
"title": "Replies",
"description": "Total number of replies to the carousel"
},
{
"name": "taps_forward",
"period": "lifetime",
"values": [
{
"value": {}
}
],
"title": "Taps Forward",
"description": "Total number of taps to see this story's next photo or video"
},
{
"name": "taps_back",
"period": "lifetime",
"values": [
{
"value": {}
}
],
"title": "Taps Back",
"description": "Total number of taps to see this story's previous photo or video"
}
]
}
Hi tried using this jq command :
.data | map(.values[].value) | #csv
This is giving the following output:
jq: error (at :70): object ({}) is not valid in a csv row
exit status 5
So when I am getting this empty JSON object it is reflecting an error.
Please Help!!
The row output should be something like
null,642,642,412,0,null,null

Answer 1

Using length==0 here is dubious at best. To check for {} one could write:
jq '.data | map(.values[].value | if . == {} then "null" else . end) | #csv'
Similarly for [].

Answer 2

If you run the command without the #csv part you will see that the output is:
[
{},
642,
412,
0,
{},
{}
]
By replacing the empty objects with "null": (length == 0)
jq '.data | map(.values[].value) | map(if (type == "object" and length == 0 ) then "null" else . end) | #csv'
Output:
"\"null\",642,412,0,\"null\",\"null\""
Per suggestion from #aaron (see comment). The following can produce the requested output without extra post-processing. Disclaimer: this is not working with my jq 1.5, but working on jqplay with jq 1.6.
jq --raw-output '.data | map(.values[].value) | map(if (type == "object" and length == 0 ) then "null" else . end) | join(",")'
Output:
null,642,412,0,null,null