1.查看所有用户
select * from all_users;
select * from dba_users;
select * from user_users;
2.查看用户或角色系统权限
select * from user_sys_privs;(当前用户的权限)
select * from role_sys_privs;(登陆用户所拥有的角色)
select * from dba_sys_privs;
3.查看所有角色
select * from dba_roles;
4.查看用户对象权限
select * from all_tab_privs;
select * from dba_tab_privs;
select * from user_tab_privs;
5.查看用户或角色所拥有的角色
select * from dba_role_privs;
select * from user_role_privs;
6.查看哪些用户有sysdba或sysoper系统权限(查询时需要相应权限)
select * from V$PWFILE_USERS
注意:用sqlplus登陆sys用户的时候,用户名应该输入:sys as sysdba,否则会报错!
在sql deverloper中新建一个sys的连接也是一样的,用户名要写为:sys as sysdba。
7.sqlplus中查看一个用户所拥有权限
SQL> select * from dba_sys_privs where grantee='username
';(username即用户名要大写才行)
8.oracle删除指定用户所有表的方法
select 'drop table' ||table_name|| ';' from all_tables where owner='要删除的用户名(注意要大写)';
9.删除用户
drop user user_nsme cascade;
10.查看当前用户下所有的表
select table_name from user_tables;
11.删除某用户下所有的表数据
select 'truncate table' || table_name from user_tables;
12.禁止外键ORACLE数据库中的外键约束名都在表user_constraints中可以查到
其中constraint_type='R'标识是外键约束
启用外键约束的命令为:altre table table_name enable constraint constraint_name
禁用外键约束的命令为:alter tabel table_name disable constraint constraint_name
然后再用SQL查出数据库中所有外键的约束名:
select 'altre table' ||table_name|| 'enable constraint' ||constraint_name|| ';' from user_constraints where constraint_type='R'
select 'altre table' ||table_name|| 'disable constraint' ||constraint_name|| ';' from user_constraints where constraint_type='R'
13.ORACLE禁用/启用外键和触发器 --启用脚本
SET SERVEROUTPUT ON SIZE 1000000
BEGIN
for c in (select 'ALTER TABLE '||TABLE_NAME||' ENABLE CONSTRAINT '||constraint_name||' ' as v_sql from user_constraints
where CONSTRAINT_TYPE='R') loop
DBMS_OUTPUT.PUT_LINE(C.V_SQL);
begin
EXECUTE IMMEDIATE c.v_sql;
exception when others then
dbms_output.put_line(sqlerrm);
end;
end loop;
for c in (select 'ALTER TABLE '||TNAME||' ENABLE ALL TRIGGERS ' AS v_sql from tab where tabtype='TABLE') loop
dbms_output.put_line(c.v_sql);
begin
execute immediate c.v_sql;
exception when others then
dbms_output.put_line(sqlerrm);
end;
end loop;
end;
/
commit;
--禁用脚本
SET SERVEROUTPUT ON SIZE 1000000
BEGIN
for c in (select 'ALTER TABLE '||TABLE_NAME||' DISABLE CONSTRAINT '||constraint_name||' ' as v_sql from user_constraints
where CONSTRAINT_TYPE='R') loop
DBMS_OUTPUT.PUT_LINE(C.V_SQL);
begin
EXECUTE IMMEDIATE c.v_sql;
exception when others then
dbms_output.put_line(sqlerrm);
end;
end loop;
for c in (select 'ALTER TABLE '||TNAME||' DISABLE ALL TRIGGERS ' AS v_sql from tab where tabtype='TABLE') loop
dbms_output.put_line(c.v_sql);
begin
execute immediate c.v_sql;
exception when others then
dbms_output.put_line(sqlerrm);
end;
end loop;
end;
/
commit;
14.查看oracel版本(2个方法)
(1).用v$versions视图: select * from v$version;
(2)query the data dictionary view PRODUCT_COMPONENT_VERSION:
15.如何在Oracle服务器上通过SQLPLUS查看本机IP地址
select sys_context('userenv','ip_address') from dual;
(tns配置,$HOME/network/admin/tnsnames.ora里面有包含IP)
https://wenda.so.com/q/1381791727061156
16.如何给表、列加注释?
SQL>comment on table 表 is '表注释';
注释已创建
SQL>comment on column 表.列 is '列注释';
注释已创建。
SQL> select * from user_tab_comments where comments is not null;
17.在ORACLE中取毫秒
select systimestamp from dual;
18.在字符串里加回车:添加一个||chr(10)
select 'Welcome to visit'||chr(10)||'www.CSDN.NET' from dual ;
19.修改oracel数据库的默认日期
alter session set nls_date_format='yyyymmddhh24miss';
20.