MSSQL MYSQL ORACLE一些常用的命令

有些不准确的，请指正

1.查看数据库版本

MSSQL: select @@version;

MySQL: select version();

ORACLE: select * from v$version;

2.查看当前用户名

MSSQL: select user_name();

MySQL: select user();

ORACLE: select user from user_tables; select username from v$session; 不知道是不是这样

3.查看当前数据库名

MSSQL: select db_name();

MySQL: select database();

Oracle: select name from v$database; show parameter db_name； 好象是多行,这个不对

oracle还有实例名

select instance_name from v$instance；

show parameter instance

4.查看所有数据库名

MSSQL: Select Name From MasteSysDatabases order By Name; 2000

SELECT NAME FROM MASTER.DBO.SYSDATABASES;2005

MySQL: show databases; select schema_name from information_schema.schemata;

Oracle:

5.查看所有表名

MSSQL: Select Name From SysObjects Where XType='U' order By Name;//'U':用户表;'S':系统表(2000);

SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES;(2005)

Mysql: show tables; select table_name from information_schema.tables where table_schema=database();

Oracle: select TABLE_NAME from all_tables;

6.查看所有列名

MSSQL: SELECT A.NAME,B.NAME FROM SYSOBJECTS A,SYSCOLUMNS B WHERE A.ID=B.ID; 2005 带表名

Select Object_Id('TableName'),Name From SysColumns ;2000是这样？好象不对

MySQL: select table_name,COLUMN_NAME from INFORMATION_SCHEMA.columns; 带表名

Oracle: select table_name,column_name from all_tab_columns;

7.查询几条记录

MSSQL: select top 5 * from xnet order by id desc;

Mysql: select * from xnet limit 0,5;

Oracle: select * from xnet where rownum=5;

oracle的一些查询

第N条记录

select * from (select rownum no,t.* from xnet t) where no=N;

第5-10条记录

select * from (select rownum no,xnet.* from xnet where rownum<=10) where no>=5;

MSSQL

第5-10条记录

select top 10 * from tablename where id not in (select top 5 id from tablename order by id asc)

其实还是MySQL方便

要查询第5到10条记录

select * from xnet limit 4,5;

8.用户管理(没有完整)

MSSQL:

新增用户

sp_addlogin 'xnet','111111','xnet_db'

添加到数据库

sp_grantdbaccess 'xnet'

sp_addrolemember 'db_owner', 'xnet' db_owner权限？

授予该用户语句权限

use xnet_db

grant create,select,update table to xnet

删除登录

EXEC sp_droplogin 'xnet'

MySQL:

grant all privieleges on database_name.* to xnet@localhost identified by 'xnet';

只给xnet对xnet_db中的table1表有select权限

grant select on xnet_db.table1 to xnet@localhost identified by 'xnet';

删除用户aaa

use mysql;

delete from user where user='aaa';

flush privileges;

修改密码:

use mysql;

update user set password=password('10086') where user='xnet';

flush privileges;

使用flush privileges命令使密码生效。

oracle:

添加一个xnet xnet_pass的用户

create user xnet identified by "xnet_pass" default tablespace TS_XNET_DATA temporary tablespace TEMP;

给用户赋予权限

grant connect to xnet;

grant resource,create session to xnet; 开发角色

grant dba to xnet;--授予DBA权限

grant unlimited tablespace to xnet;--授予不限制的表空间

grant select any table to xnet;--授予查询任何表

grant select any dictionary to xnet;--授予 查询 任何字典

删除用户

drop user xnet cascade;

9.新建数据库

MSSQL:

CREATE DATABASE Archive ON PRIMARY

(

NAME = testdb,

FILENAME ='d:\mssql\data\testdb.mdf',

SIZE = 100MB,

MAXSIZE = 200,

FILEGROWTH = 20),

LOG ON

( NAME = testlog1,

FILENAME ='d:\mssql\data\testlog1.ldf',

SIZE = 100MB,

MAXSIZE = 200,

FILEGROWTH = 20);

MySQL:CREATE DATABASE rewin;

Oracle: 有点复杂，不写了

10.备份与恢复

MSSQL:

Backup Database xnet_db To disk='d:\Backup\xnet_db_Full_20090911.bak'; 对xnet_db完全备份

restore database xnet_db from disk='d:\Backup\xnet_db_Full_20090911.bak'; 对xnet_db从完全备份中恢复

MySQL:

mysqldump -uroot -p123456 xnet_db>d:\backup\xnet_db.sql; 对xnet_db完全备份

mysql -uroot -p123456 xnet_db<d:\backup\xnet_db.sql 对xnet_db恢复

也可以用mysql命令行

mysql>use xnet_db;

mysql>source d:\backup\xnet_db.sql

Oracle:

exp USERID=system/oracle@erp owner=xnet file=d:\logback\xnet.dmp 备份用户xnet所有表和数据

imp userid=system/oracle@erp fromuser=xnet file=d:\logback\xnet.dmp ignore=y 恢复用户xnet所有表和数据
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