@Anonymous Thanks for using Microsoft Q&A forum and posting your query.
Unlike other database connectors the Pre-copy script feature is not available when ADX is used as a sink in Copy Activity. Hence you will have to take an alternative approach to clear or truncate data from the ADX table before loading new data.
Possible workaround: One possible approach is to use the lookup activity before your copy activity and execute a query that clears or truncates the table data (Note: Please ensure that your query returns a valid json response to your lookup activity).
Here's an example query that clears a table: .clear table data command
Please refer to this document where there is an sample on how to execute a Kusto query using lookup activity: Use Azure Data Factory command activity to run Azure Data Explorer management commands
In case if you have any feedback for product team to implement pre & post script feature for ADX connector, please feel free to share your feedback in IDEAS forum: https://feedback.azure.com/d365community/forum/1219ec2d-6c26-ec11-b6e6-000d3a4f032c Please do share the feedback link once it is submitted so that other users with similar feedback can up-vote and comment on your feature request to help increase the priority of the request.
I hope this info helps!
Please don’t forget to
Accept Answer and
Yes for "was this answer helpful" wherever the information provided helps you, this can be beneficial to other community members.