Function duckdb_result_get_chunk 

pub unsafe extern "C" fn duckdb_result_get_chunk(
    result: duckdb_result,
    chunk_index: idx_t,
) -> duckdb_data_chunk

DEPRECATION NOTICE**: This method is scheduled for removal in a future release.

Fetches a data chunk from the duckdb_result. This function should be called repeatedly until the result is exhausted.

The result must be destroyed with duckdb_destroy_data_chunk.

This function supersedes all duckdb_value functions, as well as the duckdb_column_data and duckdb_nullmask_data functions. It results in significantly better performance, and should be preferred in newer code-bases.

If this function is used, none of the other result functions can be used and vice versa (i.e. this function cannot be mixed with the legacy result functions).

Use duckdb_result_chunk_count to figure out how many chunks there are in the result.

@param result The result object to fetch the data chunk from. @param chunk_index The chunk index to fetch from. @return The resulting data chunk. Returns NULL if the chunk index is out of bounds.