Sequences : It is used to generate the sequence number automatically
Syntax : SQL> Create sequence
start with
Incremented by
Ex: SQL> create sequence empl_seq
start with 115
increment by 1;
Sequence created
SQL> select empl_seq.nextval from dual;
NEXTVAL
115
SQL> select empl_seq.nextval from dual;
NEXTVAL
116
SQL> select empl_seq.nextval from dual;
NEXTVAL
117
SQL> select empl_seq.CURRVAL from dual;
CURRVAL
117
Use below example to insert empno automatically by creasing
SQL> insert into emp values (empl_seq.nextval,
‘&ename’,
&sal,
‘&job’,
‘&doj’,
&deptid)
Enter value for ename: abc
Enter value for sal: 15000
Enter value for job: manager
Enter value for doj: 10-oct-12
Enter value for deptid: 555
SQL>/
Enter value for ename: kkk
Enter value for sal: 14000
Enter value for job: k
Enter value for doj: 10-mar-12
Enter value for deptid: 444
SQL> select * from emp;
check the empno is generated
Removing Sequence
SQL> Drop sequence empl_seql;