In ADF flatten a JSON result from REST

Question

Hi All,

I am trying to use fixer API for fxrate conversion using REST API feature required as an ETL step in ADF.

The below API call returns a JSON result:

https://data.fixer.io/api/latest?access_key=<myaccesskey>&base=GBP&symbols=USD

{"success":true,"timestamp":1692600783,"base":"GBP","date":"2023-08-21","rates":{"USD":1.272556}}

Next, I am applying the flatten step to get the above json in key value pair format. The unroll by dropdown does not have any selectable items. And when I preview the data:

Spark job failed: { "text/plain": "{"runId":"56e350cf-9928-4ac4-9963-115b0c58aa38","sessionId":"34d04d95-d0b7-43ad-b20a-a5f379b0032c","status":"Failed","payload":{"statusCode":400,"shortMessage":"DF-FOLDWN-001 at FoldDown 'flatten1'(Line 19/Col 8): Atleast one of unrollby or unrollMultiple expression expected","detailedMessage":"Failure 2023-08-21 06:08:55.013 failed DebugManager.processJob, run=56e350cf-9928-4ac4-9963-115b0c58aa38, errorMessage=DF-FOLDWN-001 at FoldDown 'flatten1'(Line 19/Col 8): Atleast one of unrollby or unrollMultiple expression expected"}}\n" } - RunId: 56e350cf-9928-4ac4-9963-115b0c58aa38

Please advise how to handle this scenario where I do not have any item to unroll.

Regards,

Answer 1

Hello @Srinivas Mehenderker Nath

I see that the Source JSON has no Array content!

Array can only be flattened!

I have added an Array to the payload, which can be Flatten !

As you can see we can flatten only Array!