Forum Discussion
Unable to create external table through notebook
While I am trying to create an external table reffering to the microsoft documentation:
https://learn.microsoft.com/en-us/training/modules/work-delta-lake-tables-fabric/3-create-delta-tables
df.write.format("delta").saveAsTable("myexternaltable", path="Files/myexternaltable")
spark is through error
Py4JJavaError: An error occurred while calling o7281.saveAsTable.
java.lang.AssertionError: assertion failed: Only managed tables are supported
Hi I have check the documentation online and the issue was with the lakehouse I was writting to.
Currently, Fabric only support writting external table to lakehouse without schema.
Can reffer to Note section:
https://murggu.medium.com/creating-managed-and-external-spark-tables-in-fabric-lakehouse-ef6212e75e81Hence, I changed the lakehouse with no schema. It was working fine
4 Replies
Hi I have check the documentation online and the issue was with the lakehouse I was writting to.
Currently, Fabric only support writting external table to lakehouse without schema.
Can reffer to Note section:
https://murggu.medium.com/creating-managed-and-external-spark-tables-in-fabric-lakehouse-ef6212e75e81Hence, I changed the lakehouse with no schema. It was working fine
Issue: AssertionError while creating table in Microsoft Fabric Spark
I am facing the following error while executing a Spark SQL / PySpark command to create a table in Microsoft Fabric Lakehouse:
Py4JJavaError: An error occurred while calling o402.sql
java.lang.AssertionError: assertion failed:
Only the following table types are supported:
MANAGED, MATERIALIZED_LAKE_VIEW, EXTERNALProblem Description
While creating or writing a table using Spark SQL / PySpark, the operation fails with an AssertionError. Fabric seems to reject the table definition because it is being created with a table type or storage format that Fabric does not support.
Hi RohanSingh
have you loaded a your csv/excel file into a dataframe before writing this code?
Could you please share your full code. So, that we can try to fix the issue.
Thanks!
When creating a Lakehouse, a pop-up will appear asking for the Lakehouse name. Below that, there’s a checkbox labeled "Lakehouse Schema (Public Preview)".
Make sure to uncheck this option — only then will you be able to create external managed tables in the Lakehouse.
