首先在PL/Sql中分别执行：

create or replace and compile java source named TestJava1 as 
public class TestJava1 
{ 
  public static void test() 
  { 
   System.out.println("Hello"); 
  } 
}

create or replace procedure testJava1 as language java name 'TestJava1.test()';

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在SQLPlus中

C:\Windows\System32>sqlplus nc5520110105/nc5520110105@192.168.10.87

SQL*Plus: Release 11.2.0.1.0 Production on Fri Apr 1 14:06:02 2011

Copyright (c) 1982, 2010, Oracle.  All rights reserved.

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options

SQL> set serveroutput on;
SQL> show serveroutput;
serveroutput ON SIZE UNLIMITED FORMAT WORD_WRAPPED
SQL> call dbms_java.set_output(2000);

Call completed.

SQL>
SQL> show serveroutput;
serveroutput ON SIZE UNLIMITED FORMAT WORD_WRAPPED
SQL> exec testJava1();
Hello

PL/SQL procedure successfully completed.

SQL>

---------------------------------------------------------------------------------------------------------

再看一个例子：

在PL/Sql中执行：

SQL> set serveroutput on
SQL> DECLARE a INTEGER;
  2  BEGIN
  3  myProc(1, 2, a);
  4  DBMS_OUTPUT.PUT_LINE(a);
  5  END;
  6  /
3

PL/SQL procedure successfully completed.

SQL> select myFunc(1,2) from dual;

MYFUNC(1,2)
-----------
          3

SQL>

解决方法如下：

grant SELECT ANY DICTIONARY to username;

因为v$开头的属于数据字典，通常称为动态性能视图。

今天登陆到测试环境,在做日常操作时需要使用到dual表,但是在使用了一个查询语句时(SELECT to_char(current_timestamp) FROM dual)却提示'ORA-00980: 同义词转换不再有效'错误,于是开始了这次的分析和恢复.

一、查找原因

    根据在网上搜索得到的信息判断可能是同义词丢失或者是表被删除，于是进行以下操作以确定问题。

    SELECT * FROM Dba_Objects do WHERE  do.object_type ='TABLE' AND do.object_name = 'DUAL'

    SELECT * FROM Dba_Tables dt WHERE  dt.table_name = 'DUAL'

    SELECT * FROM Dba_Synonyms ds WHERE ds.table_name = 'DUAL'

    根据以上数据字典反馈的信息确定是表被删除(因为dba_synonyms表中有此记录，表明同义词未被删除)导致此错误，决定重建该表。

二、建表操作

    由于在正式环境中该表存在，故连接到正式环境查看该表结构

    SQL> desc dual;
         Name  Type        Nullable Default Comments
         ----- ----------- -------- ------- --------
         DUMMY VARCHAR2(1) Y                        

    查看建表脚本：

    -- Create table
    create table SYS.DUAL
   (
      DUMMY VARCHAR2(1)
    )
   tablespace SYSTEM
   pctfree 10
   pctused 40
   initrans 1
   maxtrans 255
   storage
   (
    initial 104
    next 104
    minextents 1
    maxextents 505
    pctincrease 100
   );
   -- Grant/Revoke object privileges
  grant select on SYS.DUAL to PUBLIC;

有了以上内容，可以开始建表了，因为同义词后面将重新创建，所以可以在建表前删除，在操作之前使用sys重新登陆

1、DROP PUBLIC SYNONYM dual;  --删除同义词

2、create table dual
　(dummy varchar2(1))  --创建表

3、INSERT INTO dual VALUES('X')  --插入值

4、create public synonym dual for dual  --创建同义词

5、grant select on dual to public with grant option  --授权,如果不允许其它人可以将自己的权限传递给其他用户，可以去掉with后面的内容

6、退出，使用普通用户登陆，测试dual表是否能正常使用

   select sysdate from dual;

7、若测试正常则代表dual表已经被重新建立，至此，一次对dual表的恢复完成。

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/alvenz/archive/2008/12/15/3519532.aspx

select * from dba_registry where comp_id = 'JAVAVM'

为空,则未安装,请执行 $ORACLE_HOME/javavm/install/initjvm.sql安装.
创建函数

create or replace function fn_oraclecall(mArea in VARCHAR2,mDevID in Number,mPORT in Number)
return varchar2
as
language Java name 'Caller.call(java.lang.String,Integer,Integer) return Java.lang.String';

创建存储过程

create or replace procedure CHK_SETCAB_NUM
(mArea in VARCHAR2,mDevID in Number,mPORT in Number,v_out out varchar2) is
begin
v_out := fn_oraclecall(mArea,mDevID,mPORT);
end CHK_SETCAB_NUM;

loadjava

loadjava -u sys/sys@sid  -oci8 -verbose -grant user -synonym -resolve -schema user D:\Caller.jar

--这里也可以是class文件,注意兼容oracle的jre版本

注意编写的java文件里,即Caller.java的call()方法,需要是staic

Following the collapse of talks with IBM earlier this month Oracle has stepped in to acquire Sun Microsystems for $7.4bn or $9.50 a share in an all cash transaction.  This is a substantially higher valuation than IBM’s rumored price of $6.85bn.  In a statement Oracle claims that the boards of both firms have approved the deal which is expected to complete in the summer subject to regulatory approval. Oracle CEO Larry Ellison stated:

"The acquisition of Sun transforms the IT industry, combining best-in-class enterprise software and mission-critical computing systems. Oracle will be the only company that can engineer an integrated system - applications to disk - where all the pieces fit and work together so customers do not have to do it themselves. Our customers benefit as their systems integration costs go down while system performance, reliability and security go up."

The deal offers substantial additional revenue to Oracle, according President Safra Catz:

"We expect this acquisition to be accretive to Oracle's earnings by at least 15 cents on a non-GAAP basis in the first full year after closing. We estimate that the acquired business will contribute over $1.5 billion to Oracle's non-GAAP operating profit in the first year, increasing to over $2 billion in the second year. This would make the Sun acquisition more profitable in per share contribution in the first year than we had planned for the acquisitions of BEA, PeopleSoft and Siebel combined,"

There is currently very limited information available as to what Oracle plans to do with either the hardware business the drives much of Sun’s revenue, Sun’s open source software offerings such as MySQL, GlassFish, NetBeans and JavaFX, or the Java Community Process which has been central to the way Sun has managed Java's evolution, but both Sun Chairman Scott McNealy and Sun's CEO Jonathan Schwartz have issued upbeat statements. Jonathan Schwartz has been quoted as saying:

"This is a fantastic day for Sun's customers, developers, partners and employees across the globe, joining forces with the global leader in enterprise software to drive innovation and value across every aspect of the technology marketplace," said Jonathan Schwartz, Sun's CEO, "From the Java platform touching nearly every business system on earth, powering billions of consumers on mobile handsets and consumer electronics, to the convergence of storage, networking and computing driven by the Solaris operating system and Sun's SPARC and x64 systems. Together with Oracle, we'll drive the innovation pipeline to create compelling value to our customer base and the marketplace."

Sun is the latest in a number of large scale acquisitions for Oracle.  In recent years the enterprise computing giant has also acquired Siebel, PeopleSoft and BEA Systems. If Oracle is able to sell Sun's hardware business on, perhaps to Fujitsu, Oracle will have made an important acquisition as a very low price.

　　数据字典里存有用户信息、用户的权限信息、所有数据对象信息、表的约束条件、统计分析数据库的视图等。我们不能手工修改数据字典里的信息。很多时候，一般的ORACLE用户不知道如何有效地利用它。

　　dictionary　　　全部数据字典表的名称和解释，它有一个同义词dict
　　dict_column　　 全部数据字典表里字段名称和解释
 
   如果我们想查询跟索引有关的数据字典时，可以用下面这条SQL语句:
  
   SQL>select * from dictionary where instr(comments,'index')>0;
  
   如果我们想知道user_indexes表各字段名称的详细含义，可以用下面这条SQL语句:
  
   SQL>select column_name,comments from dict_columns where
table_name='USER_INDEXES';
  
   依此类推，就可以轻松知道数据字典的详细名称和解释，不用查看ORACLE的其它文档资料了。
  
   下面按类别列出一些ORACLE用户常用数据字典的查询使用方法。
  
   一、用户

   查看当前用户的缺省表空间
   SQL>select username,default_tablespace from user_users;
   查看当前用户的角色
   SQL>select * from user_role_privs;

   查看当前用户的系统权限和表级权限
   SQL>select * from user_sys_privs;
   SQL>select * from user_tab_privs;

   二、表
   
   查看用户下所有的表
   SQL>select * from user_tables;
       
   查看名称包含log字符的表
   SQL>select object_name,object_id from user_objects where instr(object_name,'LOG')>0;
   
   查看某表的创建时间
   SQL>select object_name,created from user_objects where object_name=upper
('&table_name');
   
   查看某表的大小
   SQL>select sum(bytes)/(1024*1024) as "size(M)" from user_segments where
segment_name=upper('&table_name');
   
   查看放在ORACLE的内存区里的表 
   SQL>select table_name,cache from user_tables where instr(cache,'Y')>0;
  
   三、索引
  
   查看索引个数和类别
   SQL>select index_name,index_type,table_name from user_indexes order by table_name;
　 查看索引被索引的字段
   SQL>select * from user_ind_columns where index_name=upper('&index_name');
   
   查看索引的大小
   SQL>select sum(bytes)/(1024*1024) as "size(M)" from user_segments where
segment_name=upper('&index_name');
  
   四、序列号
  
   查看序列号，last_number是当前值
   SQL>select * from user_sequences;
  
   五、视图
  
   查看视图的名称
   SQL>select view_name from user_views;
   
   查看创建视图的select语句
   SQL>select view_name,text_length from user_views;
   SQL>set long 2000;说明：可以根据视图的text_length值设定set long 的大小
   SQL>select text from user_views where view_name=upper('&view_name');
  
   六、同义词
  
   查看同义词的名称
   SQL>select * from user_synonyms;
  
   七、约束条件
  
   查看某表的约束条件
   SQL>select constraint_name, constraint_type,search_condition, r_constraint_name from
user_constraints where table_name = upper('&table_name');
       
   SQL>select c.constraint_name,c.constraint_type,cc.column_name 
   from user_constraints c,user_cons_columns cc
   where c.owner = upper('&table_owner') and c.table_name = upper('&table_name')
   and c.owner = cc.owner and c.constraint_name = cc.constraint_name
   order by cc.position;       
  
   八、存储函数和过程
  
   查看函数和过程的状态
   SQL>select object_name,status from user_objects where object_type='FUNCTION';
   SQL>select object_name,status from user_objects where object_type='PROCEDURE';
   
   查看函数和过程的源代码
   SQL>select text from all_source where owner=user and name=upper('&plsql_name');
  
   九、触发器
  
   查看触发器
   set long 50000;
   set heading off;
   set pagesize 2000;
   select
   'create or replace trigger "' ||
           trigger_name || '"' || chr(10)||
    decode( substr( trigger_type, 1, 1 ),
            'A', 'AFTER', 'B', 'BEFORE', 'I', 'INSTEAD OF' ) ||
                 chr(10) ||
    triggering_event || chr(10) ||
    'ON "' || table_owner || '"."' ||
          table_name || '"' || chr(10) ||
    decode( instr( trigger_type, 'EACH ROW' ), 0, null,
               'FOR EACH ROW' ) || chr(10) ,
    trigger_body
   from user_triggers;
本贴来自天极网群乐社区--http://q.yesky.com/group/review-17556508.html

CREATE USER "TEST"  PROFILE "DEFAULT"
IDENTIFIED BY "test" DEFAULT TABLESPACE "TEST" ;

grant connect,resource,dba to "someuser" with admin option;
 
查看当前用户的缺省表空间
    SQL>select username,default_tablespace from user_users;

查看当前用户的角色
    SQL>select * from user_role_privs;

查看当前用户的系统权限和表级权限
    SQL>select * from user_sys_privs;
    SQL>select * from user_tab_privs;

查看所有用户
    SQL>select   username   from   all_users;

C:\Documents and Settings\Administrator>emca -config dbcontrol db

EMCA 开始于 2009-2-24 17:04:05
EM Configuration Assistant 10.2.0.1.0 正式版
版权所有 (c) 2003, 2005, Oracle。保留所有权利。

输入以下信息:
数据库 SID: orcl
已为数据库 orcl 配置了 Database Control
您已选择配置 Database Control, 以便管理数据库 orcl
此操作将移去现有配置和默认设置, 并重新执行配置
是否继续? [yes(Y)/no(N)]: y
监听程序端口号: 1521
SYS 用户的口令:
DBSNMP 用户的口令:
SYSMAN 用户的口令:
SYSMAN 用户的口令: 通知的电子邮件地址 (可选): vipzhour@163.com
通知的发件 (SMTP) 服务器 (可选):
-----------------------------------------------------------------

已指定以下设置

数据库 ORACLE_HOME ................ D:\oracle\product\10.2.0\db_1

数据库主机名 ................ cst-server
监听程序端口号 ................ 1521
数据库 SID ................ orcl
通知的电子邮件地址 ............... vipzhour@163.com
通知的发件 (SMTP) 服务器 ...............

-----------------------------------------------------------------
是否继续? [yes(Y)/no(N)]: y
2009-2-24 17:06:50 oracle.sysman.emcp.EMConfig perform
信息: 正在将此操作记录到 D:\oracle\product\10.2.0\db_1\cfgtoollogs\emca\orcl\emc
a_2009-02-24_05-04-05-下午.log。
2009-2-24 17:06:57 oracle.sysman.emcp.util.DBControlUtil stopOMS
信息: 正在停止 Database Control (此操作可能需要一段时间)...

（1）用客户端连接到数据库，执行select * from v$instance
            查看version项

（2）select * from product_component_version

（3）或查询V$VERSION查看组件级信息

主要原因是表空间不够,将其设置为自动扩展即可。

alter database datafile 'D:\oracle\product\10.2.0\oradata\oracle\perfstat.dbf' autoextend on;

或者可以在创建perfstat表空间的时候进行设置：

create tablespace perfstat

datafile 'D:\oracle\product\10.2.0\oradata\oracle\perfstat.dbf' size 100m autoextend on

extend management local;

1. 工资5000以上的职员，工资减少10%
2. 工资在2000到4600之间的职员，工资增加15%

--条件1
UPDATE Personnel
SET salary = salary * 0.9
WHERE salary >= 5000;
--条件2
UPDATE Personnel
SET salary = salary * 1.15
WHERE salary >= 2000 AND salary < 4600;

UPDATE Personnel
SET salary = CASE WHEN salary >= 5000
　            THEN salary * 0.9
WHEN salary >= 2000 AND salary < 4600
THEN salary * 1.15
ELSE salary END;

UPDATE SomeTable
SET p_key = CASE WHEN p_key = 'a'
THEN 'b'
WHEN p_key = 'b'
THEN 'a'
ELSE p_key END
WHERE p_key IN ('a', 'b');

--使用IN的时候
SELECT keyCol,
CASE WHEN keyCol IN ( SELECT keyCol FROM tbl_B )
THEN 'Matched'
ELSE 'Unmatched' END Label
FROM tbl_A;
--使用EXISTS的时候
SELECT keyCol,
CASE WHEN EXISTS ( SELECT * FROM tbl_B
WHERE tbl_A.keyCol = tbl_B.keyCol )
THEN 'Matched'
ELSE 'Unmatched' END Label
FROM tbl_A;

1. 只选修一门课程的人，返回那门课程的ID
2. 选修多门课程的人，返回所选的主课程ID

--条件1：只选择了一门课程的学生
SELECT std_id, MAX(class_id) AS main_class
FROM Studentclass
GROUP BY std_id
HAVING COUNT(*) = 1;

STD_ID   MAIN_class
------   ----------
300      4
400      5
500      6

--条件2：选择多门课程的学生
SELECT std_id, class_id AS main_class
FROM Studentclass
WHERE main_class_flg = 'Y' ;

STD_ID  MAIN_class
------  ----------
100     1
200     3

SELECT  std_id,
CASE WHEN COUNT(*) = 1  --只选择一门课程的学生的情况
THEN MAX(class_id)
ELSE MAX(CASE WHEN main_class_flg = 'Y'
THEN class_id
ELSE NULL END
)
END AS main_class
FROM Studentclass
GROUP BY std_id;

STD_ID   MAIN_class
------   ----------
100      1
200      3
300      4
400      5
500      6

CASE col_1
WHEN 1    　   THEN 'Right'
WHEN NULL  THEN 'Wrong'
END