Copy Data activity - ErrorCode=FailedToUpsertDataIntoDeltaTable

Hi KerenLopez ,

Thank you for reaching out to the Microsoft Community Forum.

Please try below things to fix the issue.

1. Turn on “Enable staging” for the Copy activity:

Open your pipeline --> Copy data activity --> Settings tab. Turn on Enable staging. Re-run the pipeline.

2. Use a staging table and MERGE in a Notebook:

Change sink to Files --> Parquet or a staging Delta table. Add a Notebook activity after the copy with a simple Delta MERGE INTO from staging to the target table.

Please check below settings.

1. Make sure the sink is a Lakehouse Table (Delta) rather than the SQL endpoint of the Lakehouse. The SQL endpoint in Fabric is read-only and can’t be used as a Copy sink for upsert.

2. Verify the key columns under Table action --> Upsert are correctly mapped and present in the incoming dataset. they will cause other upsert failures.

3. Avoid temporary tables in source-side stored procedures when possible, historical issues show these can behave differently across connectors and modes. If you need, test with a simplified SELECT to isolate whether the failure is due to source-side temp objects or the sink upsert path.

Please refer below links.

Solved: Copy activity fails to save data as delta table bu... - Microsoft Fabric Community

Solved: Failed to Upsert Data into Lakehouse Delta Table –... - Microsoft Fabric Community

I hope this information helps. Please do let us know if you have any further queries.

Regards,

Dinesh