Use dual table to check sequence : Value « Sequences « Oracle PL/SQL Tutorial





SQL>
SQL> create sequence deptno_seq
  2  start with 50 increment by 10;

Sequence created.

SQL>
SQL> select deptno_seq.nextval, deptno_seq.currval
  2  from   dual;

   NEXTVAL    CURRVAL
---------- ----------
        50         50

SQL>
SQL> select deptno_seq.currval
  2  from   dual;

   CURRVAL
----------
        50

SQL>
SQL> select deptno_seq.currval, deptno_seq.nextval
  2  from   dual;

   CURRVAL    NEXTVAL
---------- ----------
        60         60

SQL>
SQL>
SQL> drop sequence deptno_seq;

Sequence dropped.










5.6.Value
5.6.1.Set start value, mini/max value and cache
5.6.2.Once initialized, you can get the current value from the sequence using currval.
5.6.3.When you select currval , nextval remains unchanged; nextval only changes when you select nextval to get the next value.
5.6.4.Query current sequence value
5.6.5.Get next value from sequence
5.6.6.select deptno_seq.currval, deptno_seq.nextval
5.6.7.Automatically including unique sequence numbers during an INSERT.
5.6.8.Use dual table to check sequence
5.6.9.Random value based on sequence
5.6.10.If id is null, use the value from sequence