Oracle碎碎念~2
1. 如何查看表的列名及类型
SQL> select column_name,data_type,data_length from all_tab_columns where owner='SCOTT' and table_name='EMP'; COLUMN_NAME DATA_TYPE DATA_LENGTH --------------- ---------- ----------- EMPNO NUMBER 22 ENAME VARCHAR2 10 JOB VARCHAR2 9 MGR NUMBER 22 HIREDATE DATE 7 SAL NUMBER 22 COMM NUMBER 22 DEPTNO NUMBER 22 8 rows selected.
2. 如何查看表的约束及建立在何列上
SQL> select * from user_cons_columns; OWNER CONSTRAINT TABLE COLUMN_NAME POSITION ----- ---------- ----- --------------- ---------- SCOTT FK_DEPTNO EMP DEPTNO 1 SCOTT PK_DEPT DEPT DEPTNO 1 SCOTT PK_EMP EMP EMPNO 1
SQL> select owner,constraint_name,constraint_type,table_name from user_constraints; OWNER CONSTRAINT C TABLE ----- ---------- - ----- SCOTT FK_DEPTNO R EMP SCOTT PK_EMP P EMP SCOTT PK_DEPT P DEPT
3. 如何查看哪个用户对具体目录的操作权限
SQL> select * from dba_tab_privs where table_name='TMP'; GRANT OWN TAB GRA PRIVILEGE GRA HIE ----- --- --- --- ------------------------ --- --- SCOTT SYS TMP SYS WRITE NO NO SCOTT SYS TMP SYS READ NO NO
4. 如何查看用户拥有的对象权限和系统权限
SQL> select * from user_tab_privs; GRANT OWN TAB GRA PRIVILEGE GRA HIE ----- --- --- --- ------------------------- --- --- SCOTT SYS TMP SYS WRITE NO NO SCOTT SYS TMP SYS READ NO NO SQL> select * from user_sys_privs; USERNAME PRIVILEGE ADM ------------------------------ ------------------------ --- SCOTT UNLIMITED TABLESPACE NO
5. 如何判断数据库启动用的是pfile还是spfile
SQL> show parameter spfile
若有值，则是用spfile启动，若为空，则是用pfile启动
6. When SQL*Plus starts, and after CONNECT commands, the site profile (e.g. $ORACLE_HOME/sqlplus/admin/glogin.sql) and the user profile (e.g. login.sql in the working directory) are run. The files may contain SQL*Plus commands.
这两个文件可以自定义SQL*Plus命令
7. sqlplus -L
-L代表Attempts to log on just once, instead of reprompting on error.即只判断一次用户名和密码是否匹配，倘若不匹配，则立即退出，如果不加L，则有三次尝试机会
[oracle@node3 ~]$ sqlplus -L scott/123 SQL*Plus: Release 11.2.0.1.0 Production on Thu Dec 18 04:07:25 2014 Copyright (c) 1982, 2009, Oracle. All rights reserved. ERROR: ORA-01017: invalid username/password; logon denied SP2-0751: Unable to connect to Oracle. Exiting SQL*Plus
8. 密码文件
密码文件的默认位置为:$ORACLE_HOME/dbs
密码文件的查找顺序：orapw<sid> --> orapw --> Failure
所以在创建密码文件时filename只能为orapw<sid>或者orapw
9. 查看谁被授予了SYSDBA或者SYSOPER权限
SQL> select * from v$pwfile_users;
10. 查看数据字典中有关权限的表
SQL> select * from dict where table_name like '%PRIVS%';
11. 批量插入
insert all
into test1
into test2
select * from dba_objects;
12. beq
[root@node2 oracle]# ipcs -m ------ Shared Memory Segments -------- key shmid owner perms bytes nattch status 0x00000000 32768 oracle 640 4096 0 0x00000000 65537 oracle 640 4096 0 0x00000000 98306 oracle 640 4096 0 0x00000000 131075 oracle 640 4096 0 0xefc07fc8 163844 oracle 640 4096 0
bytes列均为4096,而在10g下，owner列只有一个oracle用户，且bytes是一个具体的数值。为什么11g下的bytes为4096且nattch为0，具体原因可参考：http://www.oracledatabase12g.com/archives/11g%E5%86%85%E5%AD%98%E7%AE%A1%E7%90%86%E6%96%B0%E7%89%B9%E6%80%A7%E7%9A%84internal%E8%A1%A8%E7%8E%B0.html
14. 如何查看当前会话的SID
SQL> select sid from v$mystat where rownum=1;
15. 如何查看连接到当前数据库的会话
SQL> select sid,username,status from v$session;
16. 如何kill掉会话
SQL> select sid,serial# from v$session where username='SCOTT'; SID SERIAL# ---------- ---------- 19 109 SQL> alter system kill session '19,109'; System altered.
SQL> select sid,serial#,status from v$session where username='SCOTT'; SID SERIAL# STATUS ---------- ---------- -------- 19 109 KILLED
关于kill会话，可参考 http://www.cnblogs.com/kerrycode/p/4034231.html
17. 如何查看oracle用户密码
SQL> select name,password from sys.user$;
18. 不知道某个用户的密码，又想用这个用户做一些操作，又不能去修改掉这个用户的密码
以test用户为例，原来test用户的密码为test
SQL> conn test/test Connected. SQL> conn /as sysdba Connected. SQL> select name,password from sys.user$ where name='TEST'; NAME PASSWORD ------------------------------ ------------------------------ TEST 7A0F2B316C212D67 1 row selected. SQL> alter user test identified by hello; User altered. SQL> conn test/hello Connected. SQL> select * from tab; TNAME TABTYPE CLUSTERID ------------------------------ ------- ---------- CHAINED_ROWS TABLE EMPLOYEES TABLE EMPLOYEES_TMP TABLE 3 rows selected. SQL> conn /as sysdba Connected. SQL> alter user test identified by values '7A0F2B316C212D67'; User altered. SQL> conn test/test Connected.
19. 如何查看数据库属性
SQL> select property_name,property_value from database_properties;
20. 如何查看特定分区的值
SQL> select count(*) from test partition(p1);
21. 查看tablespace的数据文件
SQL> select tablespace_name,file_name from dba_data_files;
22. 查看用户被赋予的角色
SQL> select * from dba_role_privs where grantee='SCOTT';
23. 在PL/SQL Developer中如何查看表结构
CTRL+表名
24. 如何原样输出字符串
SQL> select q'([@#$%^&*~?/" '])' from dual; Q'([@#$%^&*~?/" --------------- [@#$%^&*~?/" '] SQL> select q'2I'm Victor2' from dual; Q'2I'MVICT ---------- I'm Victor
注意： 1> Q'后跟起始分隔符，起始分隔符后的字符串原样输出，起始分隔符必须有配对的结束分隔符。
2> 分隔符可以为数字、字母、特殊字符。但'&'不能作为分隔符，因为'&'意思是传入参数。
3> '['、'('、'{'作为分隔符，必须以']'、')'、'}'结束。
25. TWO_TASK
TWO_TASK lets you silently support a tns network connect string, that is, instead of: sqlplus scott/tiger@tnsname you can: export TWO_TASK=tnsname sqlplus scott/tiger <<<== that has an implied @tnsname oracle_sid is used for a local connection - direct to the server - without using a listener the environment variable name is LOCAL on windows NT. set LOCAL=service_name
TWO_TASK是环境变量，通过将其设置为网络字符串，用户通过网络登录时，可不用指定网络字符串，譬如，sqlplus scott/tiger@orcl,通过将TWO_TASK设置为orcl，用sqlplus scott/tiger可直接登录。
注意：Linux和Windows下的设置方式不同，Linux下为export TWO_TASK=orcl，Windows下为set LOCAL=orcl
26. wmsys.wm_concat
该函数可以把列值以","号分隔起来,并显示成一行
SQL> select wmsys.wm_concat(dname) from dept; WMSYS.WM_CONCAT(DNAME) -------------------------------------------------------------------------------- ACCOUNTING,RESEARCH,SALES,OPERATIONS,IT
--将逗号替换为'|'号 SQL> select replace(wmsys.wm_concat(dname),',','|') from dept; REPLACE(WMSYS.WM_CONCAT(DNAME),',','|') -------------------------------------------------------------------------------- ACCOUNTING|RESEARCH|SALES|OPERATIONS|IT
27. 如何将一行的值转换为列
原始输出如下：
SQL> select * from dept where deptno=10; DEPTNO DNAME LOC ---------- -------------- ------------- 10 ACCOUNTING NEW YORK
那么如何将这一行的值转换为列呢？
SQL> with t as 2 ( select deptno,dname,loc from dept where deptno=10) 3 select to_char(deptno) from t 4 union all 5 select dname from t 6 union all 7 select loc from t; TO_CHAR(DEPTNO) ---------------------------------------- 10 ACCOUNTING NEW YORK
28. dual
SQL> create table dual as (select * from dual union all select * from dual); Table created. SQL> select * from dual; D - X X SQL> select sysdate from dual; SYSDATE --------- 10-JUN-15 10-JUN-15
29. 生成AWR报告的三个条件，以test用户为例
grant create session to test;
grant select any dictionary to test;
grant execute on dbms_workload_repository to test;
30. 单引号对应的是chr(39)
39其实是单引号的ASCII码
31. 如何查找堵塞会话并杀掉它
SQL> select sid,serial#,blocking_session from v$session where username='SCOTT'; SID SERIAL# BLOCKING_SESSION ---------- ---------- ---------------- 125 7 142 SQL> select sid,serial#,username from V$session where sid=142; SID SERIAL# USERNAME ---------- ---------- ------------------------------ 142 27 SYS SQL> alter system kill session '142,27'; System altered.
32. 如何设置sqlprompt
首先利用define命令显示预定义的SQL*Plus变量列表
SQL>define DEFINE _DATE = "16-JUL-15" (CHAR) DEFINE _CONNECT_IDENTIFIER = "test" (CHAR) DEFINE _USER = "SCOTT" (CHAR) DEFINE _PRIVILEGE = "" (CHAR) DEFINE _SQLPLUS_RELEASE = "1102000400" (CHAR) DEFINE _EDITOR = "vim" (CHAR) DEFINE _O_VERSION = "Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - Production With the Partitioning, OLAP, Data Mining and Real Application Testing options" (CHAR) DEFINE _O_RELEASE = "1102000400" (CHAR)
设置sqlprompt
SQL>set sqlprompt &_USER@&_CONNECT_IDENTIFIER> SCOTT@test>
33. 如何查看后台进程的作用
SQL> select name,description from v$bgprocess;
34. 如何查看Oracle的版本号
SQL> select * from v$version;
35. Database Sample Schemas
http://docs.oracle.com/cd/E11882_01/server.112/e10831/toc.htm
36. 如何找出给定数之间的最大值和最小值
SQL> select least(1,2,3) from dual; LEAST(1,2,3) ------------ 1 SQL> SELECT greatest (1,2,3) from dual ; GREATEST(1,2,3) --------------- 3
37. 用shell脚本获取用户连接数
刚开始是这样：
#!/usr/bin/sh export ORACLE_HOME=/opt/app/oracle/product/11.2.0/ export TNS_ADMIN=/home/monitor sqlplus='/opt/app/oracle/product/11.2.0/bin/sqlplus' output=`$sqlplus -s test/test@orcl << EOF set feedback off; set heading off; select count(*) from v$session where status='ACTIVE'; EOF` echo $output
但是执行的时候会报如下错误：
select count(*) from v where status='ACTIVE' ERROR at line 1: ORA-04044: procedure, function, package, or type is not allowed here
原因在于$session当做变量了，当然为空了。
根据网上的方案，$前面加个转义符，即v$session修改为v\$session，但还是没有效果。
解决方法，在前面定义了一个session变量
#!/usr/bin/sh export ORACLE_HOME=/opt/app/oracle/product/11.2.0/ export TNS_ADMIN=/home/monitor session='$session' sqlplus='/opt/app/oracle/product/11.2.0/bin/sqlplus' output=`$sqlplus -s audit_vces/audit_vces@orcl << EOF set feedback off; set heading off; select count(*) from v$session where status='ACTIVE'; EOF` echo $output
【推荐】国内首个AI IDE，深度理解中文开发场景，立即下载体验Trae
【推荐】编程新体验，更懂你的AI，立即体验豆包MarsCode编程助手
【推荐】抖音旗下AI助手豆包，你的智能百科全书，全免费不限次数
【推荐】轻量又高性能的 SSH 工具 IShell：AI 加持，快人一步
· 开发者必知的日志记录最佳实践
· SQL Server 2025 AI相关能力初探
· Linux系列：如何用 C#调用 C方法造成内存泄露
· AI与.NET技术实操系列（二）：开始使用ML.NET
· 记一次.NET内存居高不下排查解决与启示
· 开源Multi-agent AI智能体框架aevatar.ai，欢迎大家贡献代码
· Manus重磅发布：全球首款通用AI代理技术深度解析与实战指南
· 被坑几百块钱后，我竟然真的恢复了删除的微信聊天记录！
· 没有Manus邀请码？试试免邀请码的MGX或者开源的OpenManus吧
· 园子的第一款AI主题卫衣上架——"HELLO! HOW CAN I ASSIST YOU TODAY