Azure流分析：按名称获取数组元素

Question

我想知道是否可以通过属性名而不是位置名来获取数组的元素。 例如，这是我的传入数据：

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

我打算将其移动到SQL数据库，并且在数据库中每个区域都有列。 问题在于，每个json中不同区域的顺序都会变化。 我成功使用以下查询，直到意识到每个json中区域的位置都发生了变化：

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 

需要一种通过名称而不是位置来引用这些字段的方法。

Answer 1

您可以使用GetArrayElement返回数组元素，然后访问每个属性。 请参考以下查询

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

Answer 2

我建议一个解决方案：在azure流作业中使用JavaScript UDF完成列排序。

请参考我的样本：

输入数据（更改顺序）：

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

js udf代码：

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;
}

您可以在obj参数中定义所需的顺序

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

输出：

希望对您有帮助。