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I am generating delta tables using data from a JSON file, pyspark, and a notebook. Everything goes by smoothly; the table creation (If it doesn't exist already) and the table overwriting. However, I can't preview the data or query it at all with SQL. If I try, I instead get the following error:
"[DELTA_READ_TABLE_WITHOUT_COLUMNS] You are trying to read a Delta table [Table Here] that does not have any columns."
This is strange, as when I check the amount of columns in the data-frame before overwriting the table using "len(df.columns)", it is considerably larger than zero.
What is also strange, is that sometimes I can view and query a table that was created in the same exact manner as a table that is problematic. It's sporradic - even with the same, unchanged data.
Looking in the lake warehouse, I find a message with a red circle and a white 'X' next to it:
And when I view the details:
...
This seems somewhat similar to a known issue I found here:
https://learn.microsoft.com/en-us/fabric/get-started/known-issues/known-issue-891-warehouse-tables-n...
I also notice this next to some (But not all) of the table names:
When I hover over it, I get a message that says: "Columns of the specified data types are not supported for...", where it then continues on to list some columns and their (presumed) types. A preview of the table can be seen.
Is the issue I'm having related to the known issue linked above and - if so - is there anything that can be done to remedy this issue? Is it possible the schema is not being inferred correctly and that could be causing all of these issues?
Hi @v-zhangtin-msft,
I don't believe "Lakehouse schemas (Public Preview)" is enabled on the lakehouse I am working with, so It likely doesn't match unfortunately.
Thank you for your time,
j_doe
Root Causes in Power BI Service:
Solutions:
Define Schema Explicitly in PySpark:
Avoid Unsupported Data Types:
Alright, I'll look into defining the schema explicitly. Thank you for your time!
Hi, @j_doe
Check out this link, does your situation match this?
Best Regards,
Community Support Team _Charlotte
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
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