Embedding Copy Activity Outputs in Array for Iteration in Azure Data Factory's ForEach Loop

Question

Can the output of a copy activity in Azure Data Factory be embedded in an array for subsequent iteration in a ForEach loop? The aim is to create an array with the outputs of multiple copy activities and then access their properties using dot notation (e.g., item().rowsRead) within the ForEach loop for validation purposes. The provided image details the code.

Answer 1

Hi @Anonymous

Welcome to Microsoft Q&A platform and thanks for posting your question.

It's possible to include the results of a copy activity in Azure Data Factory in an array. I've conducted a test to store the output of two copy activities in an array. We'll need to concatenate a string type and then convert it to a JSON type.

- We can define a variable of the array type called CopyInfo to store the output. Another variable, JsonArray, is used to view the test result in debug mode.

• In the Append Variable1 activity, I utilize @json(concat('{"activityName":"Copy1","activityObject":', activity('Copy data1').output, '}')) to store the output of the Copy data1 activity and convert it from a String type to a Json type.

• In the Append Variable2 activity, I utilize @json(concat('{"activityName":"Copy2","activityObject":',activity('Copy data2').output,'}')) to store the output of the Copy data2 activity and transform it from a String type to a Json type.

• After that, I set the value of the variable CopyInfo to the variable JsonArray.

• In the end, we can see the json array like:

"name": "JsonArray",
"value": [
    {
        "activityName": "Copy1",
        "activityObject": {
            "dataRead": 643,
            "dataWritten": 643,
            "filesRead": 1,
            "filesWritten": 1,
            ...
    },
    {
        "activityName": "Copy2",
        "activityObject": {
            "dataRead": 643,
            "dataWritten": 643,
            "filesRead": 1,
            "filesWritten": 1,
            ...
            }
    }
]

Hope this helps. Do let us know if you any further queries.

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