Converting 1-to-many json into csv - json

Question

I'm trying to parse json output from an API call. The output has an array of orders, and each order has an array of items. I want to parse the output such that I have a single CSV output of each individual item with its parent order ID.
So if a single order contains multiple items, I need the orderID repeated for each item in its order. I've read the jq documentation and dozens of samples, and I've tried some trial and error for hours. I'm SO confused as to how to do this.
I'm struggling very much with the jq parsing syntax. None of the examples are really helping, and I'm just confused. Here's the basics:
curl -s https://api.site.com/orders?page=1&pageSize=10 | jq '.'
A sample of the json is below.
{
"orders": [
{
"orderId": 217356098,
"items": [
{
"orderItemId": 327010821,
"lineItemKey": "1",
"sku": "AJC-C10S",
"name": "TestDescription",
"imageUrl": null,
"weight": null,
"quantity": 2,
"unitPrice": 106.85,
"taxAmount": null,
"shippingAmount": null,
"warehouseLocation": null,
"options": [],
"productId": null,
"fulfillmentSku": null,
"adjustment": false,
"upc": null,
"createDate": "2016-11-09T02:11:28.307",
"modifyDate": "2016-11-09T02:11:28.307"
},
{
"orderItemId": 327010822,
"lineItemKey": "1",
"sku": "AJC-C106",
"name": "AnotherTestDescription",
"imageUrl": null,
"weight": null,
"quantity": 2,
"unitPrice": 106.85,
"taxAmount": null,
"shippingAmount": null,
"warehouseLocation": null,
"options": [],
"productId": null,
"fulfillmentSku": null,
"adjustment": false,
"upc": null,
"createDate": "2016-11-09T02:11:28.307",
"modifyDate": "2016-11-09T02:11:28.307"
}
]
},
],
"total": 359934,
"page": 1,
"pages": 179968
}
Expected output (without column headers of course):
orderId,orderItemId,sku,name
217356098,327010821,"JC-C10S","TestDescription"
217356098,327010822,"JC-C106","AnotherTestDescription"
As you can see, each item has its own line, but if they came from the same order, the orderId should be repeated on each line.
How can I do this?

Answer 1

With the -r command-line option, the following jq filter:
.orders[]
| .orderId as $oid
| .items[]
| [$oid, .orderItemId, .sku, .name]
| #csv
produces the desired output.
If there's any chance that any of the selected values might be [], then consider adding a line like the following immediately before the last line above:
| map_values(if . == [] then "NONE" else . end)

Answer 2

Thanks! That worked with a slight alteration:
.orders[]
| .orderId as $oid
| .items[]
| [$oid, .items.orderItemId, .items.sku, .items.name | tostring]
| #csv