序列的创建:
-- 创建序列
CREATE SEQUENCE note_sequ ;
-- 创建留言表
CREATE TABLE note
(
id int not null primary key , -- sequence
title varchar(20) not null ,
author varchar(20) not null ,
content varchar(50) not null
) ;
-- 事务提交
commit ;
=============================================================
序列的应用:
public class NoteDAOImpl implements NoteDAO
{
// 增加操作
public void insert(Note note) throws Exception
{
String sql = "INSERT INTO note(id,title,author,content) VALUES(note_sequ.nextVal,?,?,?)" ;
PreparedStatement pstmt = null ;
DataBaseConnection dbc = null ;
dbc = new DataBaseConnection() ;
try
{
pstmt = dbc.getConnection().prepareStatement(sql) ;
pstmt.setString(1,note.getTitle()) ;
pstmt.setString(2,note.getAuthor()) ;
pstmt.setString(3,note.getContent()) ;
pstmt.executeUpdate() ;
pstmt.close() ;
}
catch (Exception e)
{
// System.out.println(e) ;
throw new Exception("操作中出现错误!!!") ;
}
finally
{
dbc.close() ;
}
}