Function duckdb_prepared_statement_column_type 

pub unsafe extern "C" fn duckdb_prepared_statement_column_type(
    prepared_statement: duckdb_prepared_statement,
    col_idx: idx_t,
) -> duckdb_type

Returns the column type of the specified column of the result of the prepared_statement.

Returns DUCKDB_TYPE_INVALID if the column is out of range.

@param prepared_statement The prepared statement to fetch the column type from. @param col_idx The column index. @return The type of the specified column.