ADF Data Flow Empty String Handling


i have problems in my Data Flow with EmptyString Handling. I made an easy example (see below) which examples my problem.

  1. Source: select '' as test (or any empty string of a table column)
  2. DerivedColumn. New Colum EmptyStringExpression with Expression iif(test == '', 'ok', 'nok') to show the problem.
  3. Sink write to table. Preview result is what i expect (see below), but in the sink table its different to the Preview, result there is 'nok'. It seems that the preview result is different to what the data flow is really writing to the sink table at the end. any help? Can't unterstand it...



preview of the sink.


result of the table with new insert row


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  1. 2022-11-11T10:40:08.757+00:00

    Yes of course. My original dataflow was ofcourse different, but with this example i can reproduce the problem that i had.