SQL Sequence :-
Sequence:
A sequence is a database item that generates a sequence of integers. We
create
the sequence using the CREATE SEQUENCE statement.
.jpg) |
| Sequence |
Syntax: Create Sequence Sequence_name
[Start
with Start_num]
[Increment
by increment_num]
[
{MAXVALUE max_num | NOMAXVALUE} ]
[
{MINVALUE min_num | NOMINVALUE} ]
[
{CYCLE | NOCYCLE} ]
[
{ORDER | NOORDER} ];
Ex:
SQL> Create Sequence medha_seq_0016
Start
with 100 Increment by 1;
Sequence
Created.
Using
the Sequence:
Ex:
SQL> Select medha_seq_0016.currval ”Currval”,
medha_seq_0016.nextval
“Nextval”
From
Dual;
Output:
Currval Nextval
---------
----------
101
101
Modifying
the Sequence: If we want to modify the sequence by using the ALTER
SEQUENCE
we can do that.
Ex:
SQL> Alter Sequence medha_seq_0016
Start
with 1000 Increment by 2;
Sequence
Altered.
Dropping
a Sequence: If we want to drop the sequence then we use this DROP
STATEMENT.
Ex:
SQL> Drop Sequence medha_seq_0016;
Sequence
Dropped.
