連帶表間的外鍵關系一起刪除所有某個用戶下的所有表：
SELECT 'DROP TABLE '||TNAME||' CASCADE CONSTRAINT ;' FROM DBA_OBJECTS FROM DBA_OBJECTS WHERE OWNER='YOUR_USER' AND OBJECT_TYPE='TABLE'
然后將選出的結果粘貼到SQLPLUS里執行
1.查看所有用戶：
select * from dba_users;
select * from all_users;
select * from user_users;
2.查看用戶或角色系統權限(直接賦值給用戶或角色的系統權限)：
select * from dba_sys_privs;
select * from user_sys_privs; (查看當前用戶所擁有的權限)
3.查看角色(只能查看登陸用戶擁有的角色)所包含的權限
sql>select * from role_sys_privs;
4.查看用戶對象權限：
select * from dba_tab_privs;
select * from all_tab_privs;
select * from user_tab_privs;
5.查看所有角色： select * from dba_roles;
6.查看用戶或角色所擁有的角色：
select * from dba_role_privs;
select * from user_role_privs;
7.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
8.SqlPlus中查看一個用戶所擁有權限
SQL>select * from dba_sys_privs where grantee='username'; 其中的username即用戶名要大寫才行。
比如： SQL>select * from dba_sys_privs where grantee='TOM';
9、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)';
10、刪除用戶
drop user user_name cascade; 如：drop user SMCHANNEL CASCADE
11、獲取當前用戶下所有的表：
select table_name from user_tables;
12、刪除某用戶下所有的表數據:
select 'truncate table ' || table_name from user_tables;
13、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'表示是外鍵約束。
啟用外鍵約束的命令為：alter table table_name enable constraint constraint_name
禁用外鍵約束的命令為：alter table table_name disable constraint constraint_name
然后再用SQL查出數據庫中所以外鍵的約束名：
select 'alter table '||table_name||' enable constraint '||constraint_name||';' from user_constraints where constraint_type='R'select 'alter table '||table_name||' disable constraint '||constraint_name||';' from user_constraints where constraint_type='R'
14、ORACLE禁用/啟用外鍵和觸發器 --啟用腳本
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;
15、當前連接數
select count(*) from v$process ;
16、最大連接數
select value from v$parameter where name ='processes';
17、當前所有用戶，按照連接數排序
select username,count(username) as con from v$session where username is not null group by username order by con desc;
18、按執行時間排序
SELECT osuser,
a.username,
cpu_time / executions / 1000000 || 's',
sql_fulltext,
machine
from v$session a, v$sqlarea b
where a.sql_address = b.address
order by cpu_time / executions desc;
19、查看用戶和默認表空間的關系。
select username,default_tablespace from dba_users;
1.查看表結構：desc表名
2.查看當前用戶的表：
select table_name from user_tables;
3.查看所有用戶的表名：
select table_name from all_tables;
4.查看所有表名(其中包括系統表)
select table_name from all_tables;
5.查看所有的表:
select * from tab/dba_tables/dba_objects/cat;
下面介紹Oracle查詢用戶表空間
Oracle查詢用戶表空間：select * fromuser_all_tables
Oracle查詢所有函數和儲存過程：select * fromuser_source
Oracle查詢所有用戶：select * fromall_users.select * from dba_users
Oracle查看當前用戶連接：select * fromv$Session
Oracle查看當前用戶權限：select * fromsession_privs
Oracle查看用戶表空間使用情況：
select a.file_id "FileNo",a.tablespace_name
"Tablespace_name",
a.bytes "Bytes",a.bytes-sum(nvl(b.bytes,0)) "Used",
sum(nvl(b.bytes,0)) "Free",
sum(nvl(b.bytes,0))/a.bytes*100 "%free"
from dba_data_files a, dba_free_space b
where a.file_id = b .file_id(+)
group by a.tablespace_name ,
a.file_id,a.bytes order by a.tablespace_name;
select
b.file_name 物理文件名,
b.tablespace_name 表空間,
b.bytes/1024/1024 大小M,
(b.bytes-sum(nvl(a.bytes,0)))/1024/1024 已使用M,
substr((b.bytes-sum(nvl(a.bytes,0)))/(b.bytes)*100,1,5) 利用率
from dba_free_space a,dba_data_files b
where a.file_id=b.file_id and b.tablespace_name='HRSM'
group by b.tablespace_name,b.file_name,b.bytes
order by b.tablespace_name
1、查看所有用戶：
select * from dba_user;
select * from all_users;
select * from user_users;
2、查看用戶系統權限：
select * from dba_sys_privs;
select * from all_sys_privs;
select * from user_sys_privs;
3、查看用戶對象權限：
select * from dba_tab_privs;
select * from all_tab_privs;
select * from user_tab_privs;
4、查看所有角色：
select * from dba_roles;
5、查看用戶所擁有的角色：
select * from dba_role_privs;
select * from user_role_privs;
6、查看角色所擁有的權限:
select * from role_sys_privs;
select * from role_tab_privs;
7、查看所有系統權限
select * from system_privilege_map;
8、查看所有對象權限
select * from table_privilege_map;
在DB2中為：
select * from syscat.dbauth
查看sid
select * from v$instance
9、Oracle查看占用表空間最大的表（排序）
select t.owner,
t.segment_name,
t.tablespace_name,
bytes / 1024 / 1024 / 1024 as sizes,
q.num_rows,
t.segment_type
from dba_segments t
left join dba_tables q
on t.segment_name = q.table_name
and t.owner = q.owner
where t.segment_type = 'TABLE'
and t.tablespace_name = 'xxx_TABLESPACE' --需要查看的表空間
and t.owner = 'xxx'
order by 4 desc
10、Oracle查看表的創建時間和最后修改時間
SELECT CREATED,LAST_DDL_TIME from user_objects where object_name=upper('表名');
CREATED 為創建時間
LAST_DDL_TIME為最后修改時間
11、Oracle中查詢某個字段新增的時間
select table_name,column_name,data_type,data_length,last_analyzed from user_tab_columns where column_name='字段名'and table_name='表名'
12、Oracle查看數據庫中表的創建時間
create table test(id int);
select created,last_ddl_time from user_objects where object_name = 'TEST';
select to_char(created, 'HH24:MI:SS') "Created" , to_char(last_ddl_time, 'HH24:MI:SS') "DDL" from user_objects where object_name = 'TEST';
select * from user_objects where object_name = 'TEST';
oracle創建用戶需要什么權限,Oracle 創建普通用戶，並賦予權限
采用sys or system / manager assysdba; 連接數據庫。
創建普通用戶oadmin: create user oadmin identified by pwd_oracle;
刪除用戶：
drop user oadmin;
授予用戶登錄數據庫的權限：
grant create session to oadmin;
授予用戶操作表空間的權限：
grant unlimited tablespace to oadmin;
grant create tablespace to oadmin;
grant alter tablespace to oadmin;
grant drop tablespace to oadmin;
grant manage tablespace to oadmin;
授予用戶操作表的權限：
grant create table to oadmin; (包含有create index權限, alter table, drop table權限)
授予用戶操作視圖的權限:
grant create view to oadmin; (包含有alter view, drop view權限)
授予用戶操作觸發器的權限：
grant create trigger to oadmin; (包含有alter trigger, drop trigger權限)
授予用戶操作存儲過程的權限：
grant create procedure to oadmin;(包含有alter procedure, drop procedure 和function 以及 package權限)
授予用戶操作序列的權限：
grant create sequence to oadmin; (包含有創建、修改、刪除以及選擇序列)
授予用戶回退段權限：
grant create rollback segment to oadmin;
grant alter rollback segment to oadmin;
grant drop rollback segment to oadmin;
授予用戶同義詞權限：
grant create synonym to oadmin;(包含drop synonym權限)
grant createpublicsynonym to oadmin;
grant droppublicsynonym to oadmin;
授予用戶關於用戶的權限：
grant create user to oadmin;
grant alter user to oadmin;
grant become user to oadmin;
grant drop user to oadmin;
授予用戶關於角色的權限：
grant create role to oadmin;
授予用戶操作概要文件的權限
grant create profile to oadmin;
grant alter profile to oadmin;
grant drop profile to oadmin;
允許從sys用戶所擁有的數據字典表中進行選擇
grant select any dictionary to oadmin;