created.
SQL> select * from dept1;
DEPTNO DNAME LOC
---------- -------------- -------------
54
56 TX
50 D50 LL50
51 D51 LL51
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
52 D52 LL52
53 D53 LL53
54 D54 LL54
DEPTNO DNAME LOC
---------- -------------- -------------
55 D55 LL55
1 D1 LL1
******序列需要调用后才会有当前值，否则是没有的。********
序列中start with不能修改，其他都可以修改
序列不连续
发生回滚
系统崩溃
被其他对象调用过
12c实现自动增长
9.同义词
对象的别名
共有的
私有的
create synonym ... for ...
SQL> grant create synonym to scott;
Grant succeeded.
SQL> l
1* grant create public synonym to scott
SQL> /
Grant succeeded.
SQL> create synonym es for empsal;
Synonym created.
SQL> desc es;
Name Null? Type
----------------------------------------- -------- ----------------------------
EMPNO NOT NULL NUMBER(4)
ENAME VARCHAR2(10)
JOB VARCHAR2(9)
MGR NUMBER(4)
HIREDATE DATE
SAL NUMBER(7,2)
COMM NUMBER(7,2)
DEPTNO NUMBER(2)
给表起个别名
SQL> desc user_synonyms
Name Null? Type
----------------------------------------- -------- ----------------------------
SYNONYM_NAME NOT NULL VARCHAR2(30)
TABLE_OWNER VARCHAR2(30)
TABLE_NAME NOT NULL VARCHAR2(30)
DB_LINK VARCHAR2(128)
公有的同义词，在当前用户下有两个同名的同义词，一个私有的，一个是共有的，访问时先访问的是私有的
SQL> desc all_synonyms
Name Null? Type
----------------------------------------- -------- ----------------------------
OWNER VARCHAR2(30)
SYNONYM_NAME VARCHAR2(30)
TABLE_OWNER VARCHAR2(30)
TABLE_NAME VARCHAR2(30)
DB_LINK VARCHAR2(128)
1.控制用户访问
系统权限
对象权限
角色权限
数据库安全性
系统安全
数据安全
create user identifued by password; 12c 公有账号(PDB)、私有账号(CDB)c##开头的
grant privilege,... to suer
SQL> desc system_privilege_map;
Name Null? Type
----------------------------------------- -------- ----------------------------
PRIVILEGE NOT NULL NUMBER
NAME NOT NULL VARCHAR2(40)
PROPERTY NOT NULL NUMBER
不同版本系统权限个数不一样，
SQL> select name from system_privilege_map;
SQL> create user u1 identified by oracle;
User created.
SQL> conn u1/oracle
ERROR:
ORA-01045: user U1 lacks CREATE SESSION privilege; logon denied
Warning: You are no longer connected to ORACLE.
SQL> conn / as sysdba
Connected.
SQL> grant create session to u1;
Grant succeeded.
SQL> grant unlimited tablespace to u1;
Grant succeeded.
11g建立用户之后有默认使用表空间的权限，而10g则没有该权限，需要给用户授予访问表空间的权限
12c cdb库必须是C##开头的，
create user c##u1 identified by oracle;
show con_name;
插件数据库启动在mont或者open状态
desc v$pdbs
select con_id,name from v$pdbs; 查看插件数据可数量
select * from user_sys_privs; 查看用户具备系统的权限
回收权限指令
revoke create table from u1;
select * from dba_sys_privs where grantee='U1';
级联授权问题
grant create table to scott with admin option; //sys
grant create table to v1;//scott
如果收回scott的create权限，此时v1的还是有create权限，但是此时的授予者变成了sys而不是scott
对象权限
SQL> grant select on scott.emp to u1;
Grant succeeded.
SQL> grant update(sal)on scott.emp to u1;
Grant succeeded.
SQL> grant select on scott.dept to u1 with grant option; 对象权限级联
Grant succeeded.
SQL> select * from user_tab_privs;
GRANTEE OWNER
------------------------------ ------------------------------
TABLE_NAME GRANTOR
------------------------------ ------------------------------
PRIVILEGE GRA HIE
---------------------------------------- --- ---
U1 SCOTT
DEPT SCOTT
SELECT YES NO
U1 SCOTT
EMP SCOTT
SELECT NO NO
GRANTEE OWNER
------------------------------ ------------------------------
TABLE_NAME GRANTOR
------------------------------ ------------------------------
PRIVIL