Azure Stream Analytics: Get Array Elements by name

Question

I was wondering if it is possible for me to get the elements of the array by the name of property than the position. For example, this is my incoming data:

    {
    "salesdata": {
        "productsbyzone": {
            "zones": [{
                    "eastzone": "shirts, trousers"
                },
                {
                    "westzone": "slacks"
                },
                {
                    "northzone": "gowns"
                },
                {
                    "southzone": "maxis"
                }
            ]
        }
    }
}

I intend to move this to a SQL database and I have columns within the database for each zone. The problem is that the order of different zones changes within each json. I was successfully using the following query until I realized that the position of the zones changes within each json:

WITH 
salesData AS
(
    SELECT
    (c.salesdata.productsbyzone.zone,0) as eastzone,
    (c.salesdata.productsbyzone.zone,1) as westzone,
    (c.salesdata.productsbyzone.zone,2) as northzone,
    (c.salesdata.productsbyzone.zone,3) as sourthzone,
    FROM [sales-data] as c
)
SELECT
eastzone.eastzone as PRODUCTS_EAST,
westzone.westzone as PRODUCTS_WEST,
northzone.northzone as PRODUCTS_NORTH,
southzone.southzone as PRODUCTS_SOUTH
INTO PRODUCTSDATABASE
FROM salesData 

Need a way to reference these fields by the name rather than by the position.

Answer 1

I recommend a solution: Use the JavaScript UDF in the azure stream job to complete the columns sort.

Please refer to my sample:

Input data(upset the order):

{
    "salesdata": {
        "productsbyzone": {
            "zones": [{
                    "westzone": "slacks"  
                },
                {
                    "eastzone": "shirts, trousers"
                },
                {
                    "northzone": "gowns"
                },
                {
                    "southzone": "maxis"
                }
            ]
        }
    }
}

js udf code:

function test(arg) {
    var z = arg;
    var obj = {
        eastzone: "",
        westzone: "",
        northzone: "",
        southzone: ""
    }   
    for(var i=0;i<z.length;i++){
        switch(Object.keys(z[i])[0]){
            case "eastzone": 
                obj.eastzone = z[i]["eastzone"];
                continue;
            case "westzone": 

                obj.westzone = z[i]["westzone"];
                continue;
            case "northzone": 

                obj.northzone = z[i]["northzone"];
                continue;
            case "southzone": 
                obj.southzone = z[i]["southzone"];
                continue;
        }
    }
    return obj;
}

You can define the order you want in the obj parameter

SQL:

WITH 
c AS
(
    SELECT 
    udf.test(jsoninput.salesdata.productsbyzone.zones) as result
    from jsoninput
),
b AS
(
  SELECT 
    c.result.eastzone as east,c.result.westzone as west,c.result.northzone as north,c.result.southzone as south
    from c
)

SELECT
    b.east,b.west,b.north,b.south
INTO
    jaycosmos
FROM
    b

Output:

Hope it helps you.

Answer 2

You can use GetArrayElement to return array element then access to each property. Please refer the below query

WITH 
salesData AS
(
    SELECT
        GetArrayElement(zones,0) as z
        FROM [sales-data] as s
)

SELECT
    z.eastzone
    z.westzone
    z.northzone
    z.southzone
FROM PRODUCTSDATABASE
FROM salesData