this DuckDB connection has no prepare(), so filter values cannot be bound. Filters are not sent rather than being interpolated into SQL.

Warnings reference › source.duckdb.unprepared

Identifier

source.duckdb.unprepared

Raised by

The grid (core)

Since

1.51.0

What happened

Filter values are bound as parameters, never interpolated into SQL text - that is what keeps a value containing a quote from becoming an injection. This connection cannot prepare statements, so the filtered query was not sent at all and no rows are returned.

The fix

Use a connection that implements prepare(). Every supported DuckDB-WASM build does.

Reference

Covered in full at the API reference.