Using a Sequence : all_sequences « System Tables Data Dictionary « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. System Tables Data Dictionary
3. all_sequences

1. A sequence generates a series of numbers.
2. A sequence contains two pseudo columns named currval and nextval.
3. Before retrieving the current value you must initialize a sequence by retrieving the next value.
4. When you select test_seq.nextval the sequence is initialized to 1.

SQL> CREATE SEQUENCE test_seq;

Sequence created.

SQL>
SQL> SELECT test_seq.nextval FROM dual;

   NEXTVAL
----------
         1

SQL>
SQL> drop sequence test_seq
  2  /

Sequence dropped.