INTERNAL Error: Primary exception: Failed to cast MySQL boolean - expected 1 byte element but got element of size %s

[cboettig]

What happens?

I am using the duckdb cli with the mysql extension to export a database from mysql to parquet. On export, I get the error:

D export database 'fbapp2024' (FORMAT PARQUET);
INTERNAL Error: Primary exception: Failed to cast MySQL boolean - expected 1 byte element but got element of size %s
Secondary exception in ExceptionFormatValue: {"exception_type":"Invalid Input","exception_message":"Invalid type specifier \"s\" for formatting a value of type int"}
This error signals an assertion failure within DuckDB. This usually occurs due to unexpected conditions or errors in the program's logic.
For more information, see https://duckdb.org/docs/dev/internal_errors

The error directs me to file an issue. The mysql database I am exporting has 214 tables. The error does not provide any information about which table is responsible for this internal error so I am not sure how to create a minimal reproducible example of the issue or how to proceed.

To Reproduce

I would be happy to share the full sql dump from the mysql (it's only ~100 MB compressed) if that helps to debug, but I haven't been able to reduce this to a nice minimal reproducible example because duckdb's error message gives me zero information about which of the 214 tables the export hit this error.

OS:

ubuntu

DuckDB Version:

1.0.0

DuckDB Client:

duckdb cli client

Full Name:

Carl Boettiger

Affiliation:

UC Berkeley

What is the latest build you tested with? If possible, we recommend testing with the latest nightly build.

I have tested with a stable release

Did you include all relevant data sets for reproducing the issue?

No - Other reason (please specify in the issue body)

Did you include all code required to reproduce the issue?

• Yes, I have

Did you include all relevant configuration (e.g., CPU architecture, Python version, Linux distribution) to reproduce the issue?

• Yes, I have

[carlopi]

I think here there is for sure an error in the formatting code within the throw in duckdb/duckdb_mysql, fixing that should make the error behave slightly better.
And likely there is also an expectation boolean values are a single byte, while here for some reason it's a multibyte. Also here expanding the error message would likely help in figuring out what should be done.

This likely it's placed in the duckdb/duckdb_mysql repo

[Mytherin]

Thanks for reporting!

I agree the error message here could be better.

Perhaps you can retry with the following settings?

SET mysql_tinyint1_as_boolean=false;
SET mysql_bit1_as_boolean=false;

[cboettig]

You nailed it in one go with like no information, amazing! This solved my issue. I will read https://duckdb.org/docs/extensions/mysql more closely next time!

[Mytherin]

I'll keep the issue open as I think the error message can definitely be improved here