The following table shows how the Oracle data types are mapped to the standard ODBC data types. Unicode Support lists Oracle to Unicode data type mappings.
18 Timestamp with timezone mapping changes based on the setting of the Fetch TSWTZ as Timestamp option only on Oracle 10g R2 and higher.
19 If the database character set is set to UTF-8, the Oracle driver maps the VARCHAR2 data type to SQL_WVARCHAR.
20 XMLType columns with binary or object relational storage are not supported.
The Oracle Wire Protocol driver does not support any object types (also known as abstract data types). When the driver encounters an object type during data retrieval, it returns an Unknown Data Type error (SQL State HY000).