Migration from Access/SQL Server to Oracle

We have a C++ application which can use either an Access database via DAO or a SQL Server database via ODBC which we would like to migrate to Oracle.

Our application makes extensive use of auto-number fields in Access, which map reasonably well to IDENTITY fields in SQL Server. Is there an equivalent in Oracle? (I've seen mention of a "sequence" field in other posts which looks interesting).

More importantly, in a few cases these auto-number/IDENTITY fields are used to link records between different tables. Both Access and SQL Server provide a feature for obtaining the last generated number for this purpose. Does Oracle provide a means for doing this via ODBC?

Thanks,

--
Randy Baker (remove Z from address in email replies)