Oracle PL/SQL Tutorial/System Tables Data Dictionary/all sequences

Get information on all the sequences you have access to using all_sequences.

   <source lang="sql">

SQL> SQL> desc all_sequences;

Name             Null?    Type
-----------------
SEQUENCE_OWNER   NOT NULL VARCHAR2(30)
SEQUENCE_NAME    NOT NULL VARCHAR2(30)
MIN_VALUE                 NUMBER
MAX_VALUE                 NUMBER
INCREMENT_BY     NOT NULL NUMBER
CYCLE_FLAG                VARCHAR2(1)
ORDER_FLAG                VARCHAR2(1)
CACHE_SIZE       NOT NULL NUMBER
LAST_NUMBER      NOT NULL NUMBER

SQL> Null? Type SQL> --select * from all_sequences;</source>

Using a Sequence

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.

   <source lang="sql">

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.</source>