Over the past few days, I've been using duckdb-rs, and for sure, there are indeed still some issues needed figured out.

When using the Appender to handle default values, it doesn't work well.

At least during my recent testing, trying to insert None::<T>, duckdb::types::Value::Null, or leaving the value unspecified all led to various errors—often resulting in fatal runtime error: Rust cannot catch foreign exceptions, aborting.

I haven’t seen a similar issue reported in duckdb-rs, but there are many related issues in duckdb. Fortunately, this particular issue has already figured out on June 7, 2024.

So maybe we need a AppendDefault.

See PR#11905, discussions#9158, issues#14343 for more.