Oracle 10g SQL Fundamentals II(学习笔记二第1-2章)

第一章用户访问
	创建用户
	create user user
	identified by passwd;
	授权
		grant privilege to user;
		grant create session,create table,create sequence,create view to scott;
		
	创建角色
	create role manager;
	grant create table,create view to manager;
	grant manager to user1,user2;
	alter user hr identified by hr;
	alter user test account lock/unlock;


	授查询权限
	grant select on employee to hr,scott;
	
	授修改部分列的权限
	grant update(department_name,location_id) 
	on departments
	to scott,manager;
	
	授管理权限
	grant select,insert on departments
	 to scott
	 with grant option;
	
	授所有用户的权限
	grant select on scott.emp
	to public;
	
	权限相关的视图
		role_sys_privs:
		role_tab_privs:
		user_role_privs:
		user_tab_privs_made:
		user_tab_privs_recd:
		user_col_privs_made:
		user_col_privs_recd:
		user_sys_privs:
	
	
	回收权限
	 revoke privilege on object from user ;
	 例如：
	  revoke select,insert on departments
	  from scott;
	  
	 第二章管理Schema对象
	 添加列：
	  alter table table_name
	  add column datatype ...;
	 
	 修改列：
	   alter table table_name
	   modify column datatype ...;
	 删除列：
	   alter table table_name
	   drop  column_name;
	 
     设置列不可用
       alter table table_name
	   set unused column_name;
	   或者
	   alter table table_name
	   set unused column column_name;
	  
	 删除不可用列
	   alter table table_name
	   drop unused columns;
	   
	 添加约束语法
	 alter table table_name
	 add constraint constraint_name ...;
	 
	 alter table emp
	 modify employee_id primary key ;
	 
	 
	 alter table emp2
	 add constraint emp_mgr_fk
	 foreign key(manager_id) references emp2(employee_id);
	 
	 alter table emp2
	 add constraint emp_dt_fk
	 foreign key(department_id)
	 refences departments on delete cascade;
	 
	 添加主键
	 alter table dept2
	 add constraint dept_id_pk
	 primary key(department_id)
	 deferrable initially deferred;
	 
	 删除约束
	 alter table emp2
	 drop constraint emp_mgr_fk;
	 
	 删除主键
	 alter table dept2
	 drop primary key  cascade;
	 
	 禁止用约束
	 alter table emp2
	 disable constraint emp_dt_fk;
	 
	 
	 启用用约束
	 alter table emp2
	 enable constraint emp_dt_fk;
	
	级联约束
	alter table emp2
	drop column employee_id cascade constraints;
	
	alter table test1
	drop (pk,fk,col1) cascade constraints;
	
	
	索引创建方式：
	   1自动创建：
	      主键创建
		  唯一主键创建
	   2手动创建
	      create index
		  create table


	为主键指定特定索引
		 create table new_emp
		 (employee_id number 
		     primary key using index
			 (create index emp_id_idx on
			  new_emp (employee_id)),
		 first_name varchar(20),
		 last_name varchar(25));
		 
		 select index_name,table_name
		 from user_indexes
		 where table_name='new_emp'
	
	
	基于特定函数的索引
	create index upper_dept_name_idx
	on dept2(upper(department_name));
	
	select * from from dept2 where upper(department_name)='SALES';
	
	删除索引
	drop index index_name;
	
	
	删除表
	drop table emp3 purge;
	
	
	flashback table 语句
	   FLASHBACK TABLE[schema.]table[,[ schema.]table ]...
          TO { TIMESTAMP | SCN } expr
          [ { ENABLE | DISABLE } TRIGGERS ];

	    select original_name,operation,droptime from recyclebin;
		
		flashback table emp2 to before drop;
		
		创建外部表
		1.创建目录
		create or replace directory emp_dir
		as '/.../emp_dir';
		2.授权
		grant read on directory emp_dir to hr;
		3.创建外部表的语法：
			CREATE TABLE <table_name> ( <col_name> <datatype>, … ) 
			ORGANIZATION EXTERNAL 
			(TYPE <access_driver_type> 
			 DEFAULT DIRECTORY <directory_name>
			 ACCESS PARAMETERS 
			  (… ) ) 
			  LOCATION ('<location_specifier>') ) REJECT LIMIT [0 | <number> | UNLIMITED]; 
		4.外部表的创建
		   CREATE TABLE oldemp (   
			fname char(25), lname CHAR(25)
		   ) 
           ORGANIZATION EXTERNAL  (
			   TYPE ORACLE_LOADER  DEFAULT DIRECTORY emp_dir 
			   ACCESS PARAMETERS  (
			   RECORDS DELIMITED BY NEWLINE   NOBADFILE   
			   NOLOGFILE   FIELDS TERMINATED BY ','   
			   (fname POSITION ( 1:20) CHAR,
			   lname POSITION (22:41) CHAR))
			   LOCATION ('emp.dat')
		   )  
		   PARALLEL 5  REJECT LIMIT 200;