How to create a SQL statement to produce nested JSON from variables? - sql

Question

I have managed to create SQL for the individual nodes, but cannot deduce how to refine the statement to include or merge both outputs.
DECLARE
#FulfillmentOrderId BIGINT = 0,
#NotifyCustomer BIT = 1,
#TrackingCompany NVARCHAR(100) = '',
#TrackingNo NVARCHAR(100) = '';
INPUT
SELECT
#NotifyCustomer AS [notify_customer],
#TrackingCompany AS [tracking_info.company],
#TrackingNo AS [tracking_info.number]
FOR JSON PATH, WITHOUT_ARRAY_WRAPPER
OUTPUT
{
"line_items_by_fulfillment_order": [
{
"fulfillment_order_id": 0
}
]
}
INPUT
SELECT (
SELECT
#FulfillmentOrderId AS [fulfillment_order_id]
FOR JSON PATH
) AS [line_items_by_fulfillment_order]
FOR JSON PATH, WITHOUT_ARRAY_WRAPPER
OUTPUT
{
"notify_customer": true,
"tracking_info": {
"company": "",
"number": ""
}
}
DESIRED OUTPUT
{
"fulfillment": {
"notify_customer": true,
"tracking_info": {
"company": "",
"number": 0
},
"line_items_by_fulfillment_order": [
{
"fulfillment_order_id": 0
}
]
}
}

Answer 1

You need to build the nested "line_items_by_fulfillment_order" JSON array and change the paths:
SELECT
#NotifyCustomer AS [fulfillment.notify_customer],
#TrackingCompany AS [fulfillment.tracking_info.company],
#TrackingNo AS [fulfillment.tracking_info.number],
(SELECT #FulfillmentOrderId AS fulfillment_order_id FOR JSON PATH) AS [fulfillment.line_items_by_fulfillment_order]
FOR JSON PATH, WITHOUT_ARRAY_WRAPPER
SQL Server 2022 introduced new JSON features, so the following statement is also an option:
SELECT JSON_OBJECT(
'fulfillment': JSON_OBJECT(
'notify_customer': #NotifyCustomer,
'tracking_info': JSON_OBJECT('company': #TrackingCompany, 'number': #TrackingNo),
'line_items_by_fulfillment_order': JSON_ARRAY(JSON_OBJECT('fulfillment_order_id': #FulfillmentOrderId))
)
)
Result:
{
"fulfillment":{
"notify_customer":true,
"tracking_info":{"company":"","number":""},
"line_items_by_fulfillment_order":[{"fulfillment_order_id":0}]
}
}