1.查看所有用戶
select * from all_users;
select * from dba_users;
select * from user_users;
2.查看用戶或角色系統權限
select * from user_sys_privs;(當前用戶的權限)
select * from role_sys_privs;(登陸用戶所擁有的角色)
select * from dba_sys_privs;
3.查看所有角色
select * from dba_roles;
4.查看用戶對象權限
select * from all_tab_privs;
select * from dba_tab_privs;
select * from user_tab_privs;
5.查看用戶或角色所擁有的角色
select * from dba_role_privs;
select * from user_role_privs;
6.查看哪些用戶有sysdba或sysoper系統權限(查詢時需要相應權限)
select * from V$PWFILE_USERS
注意:用sqlplus登陸sys用戶的時候,用戶名應該輸入:sys as sysdba,否則會報錯!
在sql deverloper中新建一個sys的連接也是一樣的,用戶名要寫爲:sys as sysdba。
7.sqlplus中查看一個用戶所擁有權限
SQL> select * from dba_sys_privs where grantee='username
';(username即用戶名要大寫纔行)
8.oracle刪除指定用戶所有表的方法
select 'drop table' ||table_name|| ';' from all_tables where owner='要刪除的用戶名(注意要大寫)';
9.刪除用戶
drop user user_nsme cascade;
10.查看當前用戶下所有的表
select table_name from user_tables;
11.刪除某用戶下所有的表數據
select 'truncate table' || table_name from user_tables;
12.禁止外鍵ORACLE數據庫中的外鍵約束名都在表user_constraints中可以查到
其中constraint_type='R'標識是外鍵約束
啓用外鍵約束的命令爲:altre table table_name enable constraint constraint_name
禁用外鍵約束的命令爲:alter tabel table_name disable constraint constraint_name
然後再用SQL查出數據庫中所有外鍵的約束名:
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/啓用外鍵和觸發器 --啓用腳本
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;
--禁用腳本
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個方法)
(1).用v$versions視圖: select * from v$version;
(2)query the data dictionary view PRODUCT_COMPONENT_VERSION:
15.如何在Oracle服務器上通過SQLPLUS查看本機IP地址
select sys_context('userenv','ip_address') from dual;
(tns配置,$HOME/network/admin/tnsnames.ora裏面有包含IP)
https://wenda.so.com/q/1381791727061156
16.如何給表、列加註釋?
SQL>comment on table 表 is '表註釋';
註釋已創建
SQL>comment on column 表.列 is '列註釋';
註釋已創建。
SQL> select * from user_tab_comments where comments is not null;
17.在ORACLE中取毫秒
select systimestamp from dual;
18.在字符串里加回車:添加一個||chr(10)
select 'Welcome to visit'||chr(10)||'www.CSDN.NET' from dual ;
19.修改oracel數據庫的默認日期
alter session set nls_date_format='yyyymmddhh24miss';
20.