Stream Analytics JSON Input query parsing - azure

Question

I am doing a POC on ingesting a JSON though EventHub, processing it through Stream job and pushing it into a Azure SQL DW.
I have worked with JSON ingestion before but the difficulty I face now is with the naming structure used in JSON.
Here is the sample:
{
"1-1": [{
"Details": [{
"FirstName": "Super",
"LastName": "Man"
}
]
}
]
}
The root element has a hyphen (-) and I am having tough time parsing through this element to access the relevant items.
I have tried the following queries and I get NULLs in the SQL tables it outputs to:
--#1
SELECT
["2-1"].Details.FirstName AS First_Name
,["2-1"].Details.LastName AS Last_Name
INTO
[SA-OUTPUT]
FROM
[SA-INPUT]
--#2
SELECT
[2-1].Details.FirstName AS First_Name
,[2-1].Details.LastName AS Last_Name
INTO
[SA-OUTPUT]
FROM
[SA-INPUT]
--#3
SELECT
2-1.Details.FirstName AS First_Name
,2-1.Details.LastName AS Last_Name
INTO
[SA-OUTPUT]
FROM
[SA-INPUT]
--#4
SELECT
SA-INPUT.["2-1"].Details.FirstName AS First_Name
,SA-INPUT.["2-1"].Details.LastName AS Last_Name
INTO
[SA-OUTPUT]
FROM
[SA-INPUT]
Would appreciate the correct way to do this.
Thanks in advance.

Answer 1

Your JSON schema is nested but also has some arrays. In order to read the data you will need to use the GetArrayElement function.
Here's a query that will read your sample data:
WITH Step1 AS(
SELECT GetArrayElement([1-1], 0) as FirstLevel
FROM iothub),
Step2 AS(
SELECT GetArrayElement(FirstLevel.Details,0) SecondLevel
FROM Step1)
SELECT SecondLevel.FirstName, SecondLevel.LastName from Step2
For more info, you can have a look at our page Work with complex Data Types in JSON and AVRO.
Let me know if you have any question.
Thanks,
JS (ASA team)

Answer 2

It tried and it worked beautifully. If lets say I have to generate data from two separate array elements, I would have to create two separate CTEs.
{
"1-1": [{
"Details": [{
"FirstName": "Super",
"LastName": "Man"
}
]
}
]
},
{
"2-1": [{
"Address": [{
"Street": "Main",
"Lane": "Second"
}
]
}
]
}
How do I merge elements from two CTEs into one output query? I can only refer CTE in the following line.