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

Home
Oracle PL/SQL Tutorial
1.Introduction
2.Query Select
3.Set
4.Insert Update Delete
5.Sequences
6.Table
7.Table Joins
8.View
9.Index
10.SQL Data Types
11.Character String Functions
12.Aggregate Functions
13.Date Timestamp Functions
14.Numerical Math Functions
15.Conversion Functions
16.Analytical Functions
17.Miscellaneous Functions
18.Regular Expressions Functions
19.Statistical Functions
20.Linear Regression Functions
21.PL SQL Data Types
22.PL SQL Statements
23.PL SQL Operators
24.PL SQL Programming
25.Cursor
26.Collections
27.Function Procedure Packages
28.Trigger
29.SQL PLUS Session Environment
30.System Tables Data Dictionary
31.System Packages
32.Object Oriented
33.XML
34.Large Objects
35.Transaction
36.User Privilege
Oracle PL/SQL Tutorial » Sequences » Value 
5.6.8.Use dual table to check sequence
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
java2s.com  | Contact Us | Privacy Policy
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.