1-- For oracle 12c or later
2-- auto inc
3create table t1 (
4 c1 NUMBER GENERATED by default on null as IDENTITY,
5 c2 VARCHAR2(10)
6 );
7-- More options for initial value and increment value
8create table t1 (
9 c1 NUMBER GENERATED ALWAYS as IDENTITY(START with 1 INCREMENT by 1),
10 c2 VARCHAR2(10)
11 );