edubraqd opened a new issue, #24911:
URL: https://github.com/apache/datafusion/issues/24911

   ### Describe the bug
   
   `unnest` on a struct is only supported as the top-level select expression. 
Using it anywhere else hits `assert_or_internal_err!(struct_allowed, ...)` in 
`RecursiveUnnestRewriter::transform` (`datafusion/sql/src/utils.rs`), so the 
user gets an *internal* error that asks them to file a bug, even though the 
condition is entirely determined by the shape of their query.
   
   ### To Reproduce
   
   ```sql
   SELECT unnest(unnest(struct([1])));
   SELECT unnest(struct(1))['c0'];
   ```
   
   ```text
   Internal error: Assertion failed: struct_allowed: unnest on struct can only 
be applied at the root level of select expression.
   This issue was likely caused by a bug in DataFusion's code. Please help us 
to resolve this by filing a bug report in our issue tracker: 
https://github.com/apache/datafusion/issues
   ```
   
   `unnest.slt` even has a test (`select arrow_typeof(unnest(column5)) from 
unnest_table`) that pins this internal-error text.
   
   ### Expected behavior
   
   ```text
   Error during planning: unnest on struct can only be applied at the root 
level of select expression
   ```
   
   ### Additional context
   
   Found while running a corpus of unusual `unnest` expressions against 
`datafusion-cli`.
   


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to