Oracle driver problem

When you use sql functions like SUBSTR, which requires more than one parameter, the final mapping is incorrect.

Example:
select substr(field_1, 1, 6) as renamed_field, field_2 from table;

Expected mapping:
array('renamed_field' => 'value1', 'field_2' => 'value2');

Current mapping:
array('substr(field_1' => 'value1', '1' => 'value2');