SQL Server - JSON Handling Unknown First Element - json

Question

I am capturing JSON data from a number of services sources to a table in SQL Server; where it is queued for processing. Each of the data sources has a different initial element to identify the type. A fictional example is below.
I can query the content of the file easily enough using json_value (example below) or json_query. What I'm struggling to figure out is identifying which type of file i have in order to commence processing. The identifier is the name of first element "AddressDetails" in the example below. Is there a way in SQL's json querying to get the name of the first element out? Or do I need to push that up to the service that is receiving the data and save the type with the json data?
declare #test table (jsondata nvarchar(max))
insert into #test
select '{
"AddressDetails": {
"type": 1,
"address": {
"Street1": "A Street",
"Street2": "",
"town": "Bristol",
"county": "Avon",
"country": "England"
}
}
} '
select
json_value(jsondata, '$.AddressDetails."type"'),
json_value(jsondata, '$.AddressDetails.address."Street1"'),
json_value(jsondata, '$.AddressDetails.address."Street2"'),
json_value(jsondata, '$.AddressDetails.address."town"'),
json_value(jsondata, '$.AddressDetails.address."county"'),
json_value(jsondata, '$.AddressDetails.address."country"')
from #test

Answer 1

Suppose your structure will remain the same, except the first identifier
you can use the following dynamic part:
UPDATE
SET NOCOUNT ON
IF OBJECT_ID ('tempdb..##Test') IS NOT NULL DROP TABLE ##Test
CREATE TABLE ##TEST (jsondata nvarchar(max))
DECLARE #Cmd NVARCHAR(MAX)=''
insert into ##TEST
select '{
"NameOfIdentifier": {
"type": 1,
"address": {
"Street1": "A Street",
"Street2": "",
"town": "Bristol",
"county": "Avon",
"country": "England"
}
}
}'
SELECT #Cmd+= 'SELECT DISTINCT '''+[Key]+''' as Identifier FROM ##TEST
CROSS APPLY OPENJSON(jsondata ,'''+'$.'+[Key]+''');'
FROM ##TEST
CROSS APPLY OPENJSON (jsondata )
EXEC sp_executesql #Cmd
DROP TABLE ##TEST
you'll get the following result:
Let me know if this helps