в 13:45, 26 мая 2010

2010-05-26T13:45:46Z

Admin: 1 версия

2010-05-26T10:07:51Z

1 версия

Новая страница

== 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==

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



<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>

← Предыдущая	Версия 13:45, 26 мая 2010
(нет различий)

Oracle PL/SQL Tutorial/System Tables Data Dictionary/all sequences - История изменений

в 13:45, 26 мая 2010

Admin: 1 версия