oracle常用sql语句
Plus system/manager2、显示当前连接用户SQL> show user3、查看系统拥有哪些用户SQL> select * from all_users;4、新建用户并授权SQL> create user a identified by a;（默认建在SYSTEM表空间下）SQL> grant connect,resource to a;5、连接到新用户SQL> conn a/a6、查询当前用户下所有对象SQL> select * from tab;7、建立第一个表SQL> create table a(a number);8、查询表结构SQL> desc a9、插入新记录SQL> insert into a values(1);10、查询记录SQL> select * from a;11、更改记录SQL> update a set a=2;12、删除记录SQL> delete from a;13、回滚SQL> roll;SQL> rollback;14、提交SQL> commit;用户授权:GRANT ALTER ANY INDEX TO "user_id "GRANT "dba " TO "user_id ";ALTER USER "user_id " DEFAULT ROLE ALL创建用户:CREATE USER "user_id " PROFILE "DEFAULT " IDENTIFIED BY " DEFAULT TABLESPACE"USERS " TEMPORARY TABLESPACE "TEMP " ACCOUNT UNLOCK;GRANT "CONNECT " TO "user_id ";用户密码设定:ALTER USER "CMSDB " IDENTIFIED BY "pass_word "表空间创建:CREATE TABLESPACE "table_space " LOGGING DATAFILE'C:\ORACLE\ORADATA\dbs\table_space.ora' SIZE 5M------------------------------------------------------------------------1、查看当前所有对象SQL > select * from tab;2、建一个和a表结构一样的空表SQL > create table b as select * from a where 1=2;SQL > create table b(b1,b2,b3) as select a1,a2,a3 from a where 1=2;3、察看数据库的大小，和空间使用情况SQL > col tablespace format a20SQL > select b.file_id 文件ID, b.tablespace_name 表空间, b.file_name 物理文件名, b.bytes 总字节数, (b.bytes-sum(nvl(a.bytes,0))) 已使用, sum(nvl(a.bytes,0)) 剩余, sum(nvl(a.bytes,0))/(b.bytes)*100 剩余百分比 from dba_free_space a,dba_data_files b where a.file_id=b.file_id group by b.tablespace_name,b.file_name,b.file_id,b.bytes order by b.tablespace_name / dba_free_space --表空间剩余空间状况 dba_data_files --数据文件空间占用情况4、查看现有回滚段及其状态SQL > col segment format a30SQL > SELECT SEGMENT_NAME,OWNER,TABLESPACE_NAME,SEGMENT_ID,FILE_ID,STATUS FROMDBA_ROLLBACK_SEGS;5、查看数据文件放置的路径SQL > col file_name format a50SQL > select tablespace_name,file_id,bytes/1024/1024,file_name fromdba_data_files order by file_id;6、显示当前连接用户SQL > show user7、把SQL*Plus当计算器SQL > select 100*20 from dual;8、连接字符串SQL > select 列1 | |列2 from 表1;SQL > select concat(列1,列2) from 表1;9、查询当前日期SQL > select to_char(sysdate,'yyyy-mm-dd,hh24:mi:ss') from dual;10、用户间复制数据SQL > copy from user1 to user2 create table2 using select * from table1;11、视图中不能使用order by，但可用group by代替来达到排序目的SQL > create view a as select b1,b2 from b group by b1,b2;12、通过授权的方式来创建用户SQL > grant connect,resource to test identified by test;SQL > conn test/test13、查出当前用户所有表名。select unique tname from col;-----------------------------------------------------------------------
alter table alist_table add address varchar2(100);
alter table alist_table modify address varchar2(80);
create table alist_table_copy as select ID,NAME,PHONE,EMAIL,QQ as QQ2,ADDRESS from alist_table;drop table alist_table;rename alist_table_copy to alist_table
空值处理有时要求列值不能为空create table dept (deptno number(2) not null, dname char(14), loc char(13));在基表中增加一列alter table deptadd (headcnt number(3));修改已有列属性alter table deptmodify dname char(20);注：只有当某列所有值都为空时，才能减小其列值宽度。只有当某列所有值都为空时，才能改变其列值类型。只有当某列所有值都为不空时，才能定义该列为not null。例：alter table dept modify (loc char(12));alter table dept modify loc char(12);alter table dept modify (dname char(13),loc char(12));查找未断连接select process,osuser,username,machine,logon_time ,sql_textfrom v$session a,v$sqltext b whe
正在看的ORACLE教程是:oracle常用sql语句。re a.sql_address=b.address;-----------------------------------------------------------------1.以USER_开始的数据字典视图包含当前用户所拥有的信息, 查询当前用户所拥有的表信息:select * from user_tables;2.以ALL_开始的数据字典视图包含ORACLE用户所拥有的信息,查询用户拥有或有权访问的所有表信息:select * from all_tables;3.以DBA_开始的视图一般只有ORACLE数据库管理员可以访问:select * from dba_tables;4.查询ORACLE用户：conn sys/change_on_installselect * from dba_users;conn system/manager;select * from all_users;5.创建数据库用户：CREATE USER user_name IDENTIFIED BY password;GRANT CONNECT TO user_name;GRANT RESOURCE TO user_name;授权的格式: grant (权限) on tablename to username;删除用户(或表):drop user(table) username(tablename) (cascade);6.向建好的用户导入数据表IMP SYSTEM/MANAGER FROMUSER = FUSER_NAME TOUSER = USER_NAME FILE = C:\EXPDAT.DMPCOMMIT = Y7.索引create index [index_name] on [table_name]( "column_name ")
转载于:https://www.cnblogs.com/quanwei/archive/2009/07/15/1524314.html
