How to create a table with an auto increment column in oracle 12c?

Yes, it is possible to create a table having  an identity column.And it enables us to automatically insert data on primary column of a table without the need of an oracle sequence database object .

We use the GENERATE AS IDENTITY clause to create the identity column.

Example:

SQL> conn mereba/mereba@orcl
Connected.

--- create a table with autoincrement column
SQL> create table sttms_cust_account(
  2  cust_no number generated as identity
  3  ,ac_desc varchar2(30 char));
 Table created.

---insert data
 SQL> insert into sttms_cust_account(ac_desc) values('Messi Dave');
 1 row created.

--- view the data
 SQL> select * from sttms_cust_account;
    CUST_NO AC_DESC
---------- ------------------------------
         1 Messi Dave
 SQL>