Transforming JSON data and child objects into rows within MSSQL - json

Question

My very first question after using this site for my own learning! Still a beginner so go easy on me :)
I am trying to format JSON data within MSSQL Server. I have a static JSON file which I can get to display via OPENROWSET, and populate a variable. This JSON file has a "header" and then one or more "child" rows, basically an order header and order detail lines. I can successfully separately display the header's columns as a table in a result-set. I'd like to do the same with just the detail lines - the aim being to then store the header in a table and it's details in a table within SQL server - this part I'll have no issue with.
Here is some mock-up JSON data that I'm working with. This is the exact format I need to use, so I don't have any room to manoeuvre with it but I've populated it with test data:
{
"InputParameters" : {
"P_IN_ORDER_SOURCE" : "The_Web",
"P_IN_ORIG_SYS_DOCUMENT_REF" : "Order666",
"P_IN_SOLD_TO_CUST_NUMBER" : "JOEB11",
"P_IN_CUST_ORDER_NUMBER" : "JoeB5556667",
"P_IN_REQUEST_DATE" : "2021-01-20 08:10:06",
"P_IN_ORDER_ENTRY_DATE" : "2021-01-20 08:10:06",
"P_IN_SHIPTO_NAME" : "The Testing Co.",
"P_IN_SHIPTO_ADDR" : "82 Annweir Crescent",
"P_IN_SHIPTO_ADDR_2" : null,
"P_IN_SHIPTO_CITY" : "Atlantis",
"P_IN_SHIPTO_STATE" : "WSX",
"P_IN_SHIPTO_ZIP" : "AT55 666",
"P_IN_SHIPTO_COUNTRY" : "GB",
"P_IN_OPERATION_CODE" : "CREATE",
"P_IN_BOOKED_FLAG" : "N",
"P_IN_OU_NAME" : "ATL UK OU",
"P_IN_SPECIAL_INSTRUCTIONS" : null,
"P_IN_QUOTE_NUMBER" : null,
"P_IN_PRICELIST_ID" : "8",
"P_IN_EMAIL" : "testemail#testemail.com",
"P_IN_SHIPTO_COUNTY" : null,
"P_IN_SHIPPING_METHOD" : "Pre 930",
"P_IN_SHIPPING_INSTRUCTIONS" : null,
"P_IN_ATTENTION_TO" : "Joe Bloggs",
"P_IN_FREIGHT_CARRIER_CODE" : null,
"P_IN_IS_RETURN" : null,
"P_IN_SALES_REP" : null,
"P_IN_LINE_DATA" : [ {
"P_IN_LINE_DATA_ITEM" : [ {
"ORIG_SYS_DOCUMENT_REF" : "Order666",
"ORIG_SYS_LINE_REF" : "1",
"CUSTOMER_LINE_NUMBER" : "1",
"ITEM_TYPE_CODE" : "STANDARD",
"ITEM_DESCRIPTION" : "SKU7776",
"USER_ITEM_DESCRIPTION" : "SKU7776",
"TOP_MODEL_LINE_REF" : null,
"LINK_TO_LINE_REF" : null,
"COMPONENT_CODE" : null,
"ORDERED_QUANTITY" : "6",
"ORDER_QUANTITY_UOM" : null,
"UNIT_LIST_PRICE" : "16.95",
"UNIT_SELLING_PRICE" : "16.95",
"CALCULATE_PRICE_FLAG" : "N",
"OPERATION_CODE" : "INSERT"
}, {
"ORIG_SYS_DOCUMENT_REF" : "Order666",
"ORIG_SYS_LINE_REF" : "2",
"CUSTOMER_LINE_NUMBER" : "2",
"ITEM_TYPE_CODE" : "STANDARD",
"ITEM_DESCRIPTION" : "SKU12345",
"USER_ITEM_DESCRIPTION" : "SKU12345",
"TOP_MODEL_LINE_REF" : null,
"LINK_TO_LINE_REF" : null,
"COMPONENT_CODE" : null,
"ORDERED_QUANTITY" : "6",
"ORDER_QUANTITY_UOM" : null,
"UNIT_LIST_PRICE" : "11.89",
"UNIT_SELLING_PRICE" : "11.89",
"CALCULATE_PRICE_FLAG" : "N",
"OPERATION_CODE" : "INSERT"
}, {
"ORIG_SYS_DOCUMENT_REF" : "Order666",
"ORIG_SYS_LINE_REF" : "3",
"CUSTOMER_LINE_NUMBER" : "3",
"ITEM_TYPE_CODE" : "STANDARD",
"ITEM_DESCRIPTION" : "SKU9999",
"USER_ITEM_DESCRIPTION" : "SKU9999",
"TOP_MODEL_LINE_REF" : null,
"LINK_TO_LINE_REF" : null,
"COMPONENT_CODE" : null,
"ORDERED_QUANTITY" : "8",
"ORDER_QUANTITY_UOM" : null,
"UNIT_LIST_PRICE" : "46.42",
"UNIT_SELLING_PRICE" : "46.42",
"CALCULATE_PRICE_FLAG" : "N",
"OPERATION_CODE" : "INSERT"
} ]
} ]
}
}
I've been trying to learn how to use this JSON with SQL server pretty much starting from today. I've explored the OPENJSON() function which like I've said, I can define the separate columns and path with the header information - but as soon as I try to do similar and path to the detail objects, I just get NULLs back in each column.
Any suggestions at all? Apologies if I've missed any key information out here! Many thanks!

Answer 1

Something like this:
declare #json nvarchar(max) = '
{
"InputParameters" : {
"P_IN_ORDER_SOURCE" : "The_Web",
"P_IN_ORIG_SYS_DOCUMENT_REF" : "Order666",
"P_IN_SOLD_TO_CUST_NUMBER" : "JOEB11",
"P_IN_CUST_ORDER_NUMBER" : "JoeB5556667",
"P_IN_REQUEST_DATE" : "2021-01-20 08:10:06",
"P_IN_ORDER_ENTRY_DATE" : "2021-01-20 08:10:06",
"P_IN_SHIPTO_NAME" : "The Testing Co.",
"P_IN_SHIPTO_ADDR" : "82 Annweir Crescent",
"P_IN_SHIPTO_ADDR_2" : null,
"P_IN_SHIPTO_CITY" : "Atlantis",
"P_IN_SHIPTO_STATE" : "WSX",
"P_IN_SHIPTO_ZIP" : "AT55 666",
"P_IN_SHIPTO_COUNTRY" : "GB",
"P_IN_OPERATION_CODE" : "CREATE",
"P_IN_BOOKED_FLAG" : "N",
"P_IN_OU_NAME" : "ATL UK OU",
"P_IN_SPECIAL_INSTRUCTIONS" : null,
"P_IN_QUOTE_NUMBER" : null,
"P_IN_PRICELIST_ID" : "8",
"P_IN_EMAIL" : "testemail#testemail.com",
"P_IN_SHIPTO_COUNTY" : null,
"P_IN_SHIPPING_METHOD" : "Pre 930",
"P_IN_SHIPPING_INSTRUCTIONS" : null,
"P_IN_ATTENTION_TO" : "Joe Bloggs",
"P_IN_FREIGHT_CARRIER_CODE" : null,
"P_IN_IS_RETURN" : null,
"P_IN_SALES_REP" : null,
"P_IN_LINE_DATA" : [ {
"P_IN_LINE_DATA_ITEM" : [ {
"ORIG_SYS_DOCUMENT_REF" : "Order666",
"ORIG_SYS_LINE_REF" : "1",
"CUSTOMER_LINE_NUMBER" : "1",
"ITEM_TYPE_CODE" : "STANDARD",
"ITEM_DESCRIPTION" : "SKU7776",
"USER_ITEM_DESCRIPTION" : "SKU7776",
"TOP_MODEL_LINE_REF" : null,
"LINK_TO_LINE_REF" : null,
"COMPONENT_CODE" : null,
"ORDERED_QUANTITY" : "6",
"ORDER_QUANTITY_UOM" : null,
"UNIT_LIST_PRICE" : "16.95",
"UNIT_SELLING_PRICE" : "16.95",
"CALCULATE_PRICE_FLAG" : "N",
"OPERATION_CODE" : "INSERT"
}, {
"ORIG_SYS_DOCUMENT_REF" : "Order666",
"ORIG_SYS_LINE_REF" : "2",
"CUSTOMER_LINE_NUMBER" : "2",
"ITEM_TYPE_CODE" : "STANDARD",
"ITEM_DESCRIPTION" : "SKU12345",
"USER_ITEM_DESCRIPTION" : "SKU12345",
"TOP_MODEL_LINE_REF" : null,
"LINK_TO_LINE_REF" : null,
"COMPONENT_CODE" : null,
"ORDERED_QUANTITY" : "6",
"ORDER_QUANTITY_UOM" : null,
"UNIT_LIST_PRICE" : "11.89",
"UNIT_SELLING_PRICE" : "11.89",
"CALCULATE_PRICE_FLAG" : "N",
"OPERATION_CODE" : "INSERT"
}, {
"ORIG_SYS_DOCUMENT_REF" : "Order666",
"ORIG_SYS_LINE_REF" : "3",
"CUSTOMER_LINE_NUMBER" : "3",
"ITEM_TYPE_CODE" : "STANDARD",
"ITEM_DESCRIPTION" : "SKU9999",
"USER_ITEM_DESCRIPTION" : "SKU9999",
"TOP_MODEL_LINE_REF" : null,
"LINK_TO_LINE_REF" : null,
"COMPONENT_CODE" : null,
"ORDERED_QUANTITY" : "8",
"ORDER_QUANTITY_UOM" : null,
"UNIT_LIST_PRICE" : "46.42",
"UNIT_SELLING_PRICE" : "46.42",
"CALCULATE_PRICE_FLAG" : "N",
"OPERATION_CODE" : "INSERT"
} ]
} ]
}
}
'
select *
from openjson(#json,'$.InputParameters.P_IN_LINE_DATA[0].P_IN_LINE_DATA_ITEM')
with
(
ORIG_SYS_DOCUMENT_REF varchar(200),
ORIG_SYS_LINE_REF int,
CUSTOMER_LINE_NUMBER int,
ITEM_TYPE_CODE varchar(200),
-- . . .
OPERATION_CODE varchar(200)
)