Function duckdb_prepared_statement_column_count 

pub unsafe extern "C" fn duckdb_prepared_statement_column_count(
    prepared_statement: duckdb_prepared_statement,
) -> idx_t

Returns the number of columns present in a the result of the prepared statement. If any of the column types are invalid, the result will be 1.

@param prepared_statement The prepared statement. @return The number of columns present in the result of the prepared statement.