Postgres _varchar can panic on Option.unwrap

[auyer]

What language are you using?

Python

What version are you using?

0.3.2a4

What database are you using?

PostgreSQL

What dataframe are you using?

Arrow

Can you describe your bug?

Reading a varchar array can return error thread '<unnamed>' panicked at 'called Option::unwrap()on aNone value'
I was not able to figure out what row in my database led to this error because its a large base, and my PR fixes the issue already. But it would be interesting to figure this out and add it as a test condition.

What are the steps to reproduce the behavior?

If possible, please include a minimal simple example including:

Database setup if the error only happens on specific data or data type

CREATE TABLE mytable (
	id varchar(36) NOT NULL,
	arraycolumn _varchar NULL DEFAULT '{}'::character varying[],
);

Example query / code

SELECT  arraycolumn FROM mytable

What is the error?

RUST_BACKTRACE=full python main.py
[11:03:25] {/home/auyer/.local/lib/python3.10/site-packages/botocore/credentials.py:1255} INFO - Found credentials in shared credentials file: ~/.aws/credentials
[11:03:25] {/home/auyer/work/coding/datachapter-elts/python-container/polars-extraction/main.py:142} INFO - READING DATASET FROM DATABASE FROM TABLE orders
thread '<unnamed>' panicked at 'called `Option::unwrap()` on a `None` value', /__w/connector-x/connector-x/connectorx/src/destinations/arrow2/arrow_assoc.rs:451:21
...
Traceback (most recent call last):
  File "/home/auyer/work/coding/datachapter-elts/python-container/polars-extraction/main.py", line 319, in <module>
    main()
  File "/home/auyer/work/coding/datachapter-elts/python-container/polars-extraction/main.py", line 299, in main
    overwriteMode(conn)
  File "/home/auyer/work/coding/datachapter-elts/python-container/polars-extraction/main.py", line 143, in overwriteMode
    df = read_sql(query, conn).lazy()
  File "/home/auyer/work/coding/datachapter-elts/python-container/polars-extraction/main.py", line 111, in read_sql
    df = cx.read_sql(
  File "/home/auyer/.local/lib/python3.10/site-packages/connectorx/__init__.py", line 297, in read_sql
    result = _read_sql(
pyo3_runtime.PanicException: called `Option::unwrap()` on a `None` value