如何直接在 Azure 数据工厂管道中转换 JSON 数据

Question

I have a lookup in a Azure Data Factory pipeline which is connected to a data flow. The lookup returns a JSON array in the form:

[
    {
        "COLUMN_NAME": "country_code"
    },
    {
        "COLUMN_NAME": "customer_role"
    },
    {
        "COLUMN_NAME": "valid_from"
    },
    {
        "COLUMN_NAME": "valid_to"
    }
]

The data flow accepts an array of strings as parameter. Therefore I need a way to transform the data from the lookup to an array of strings in the form:

[
    "country_code",
    "customer_role",
    "valid_from",
    "valid_to"
]

In my pipeline the output from the lookup is available as pipeline expression: @activity('GetKeyColumns').output.value .

For the data flow I can choose if I will use data flow expression or a pipeline expression to pass the parameter (array of strings). The data flow expression has a map function which is able to map the data structure. But I have no idea how I can use the output from the lookup in this function.

Is there a way how I can achieve this transformation in my pipeline?

Answer 1

You can add a variable, type is array, then use For Each activity and append variable activity.

Step:

1.create a variable named string_array

2.create a For Each activity,expression: @activity('GetKeyColumns').output.value

3.create a Append variable activity inside For each avtivity,expression: @item()['COLUMN_NAME']

4.pass string_array to data flow by using pipeline expression: @variables('string_array')