【总结】Oracle恢复误删除数据,解除锁定的等SQL语句

sdxrh2005 贡献于2012-11-11

作者 dell  创建于2012-11-11 10:05:45   修改者  修改于1899-12-30 00:00:00字数10799

文档摘要:1.曾经不小心把开发库的数据库表全部删除,当时吓的要死。结果找到下面的语句恢复到了1个小时之前的数据!很简单。注意使用管理员登录系统:select*from表名asoftimestampsysdate-1/12//查询两个小时前的某表数据!既然两小时以前的数据都得到了,继续怎么做,知道了吧。
关键词:

1.曾经不小心把开发库的数据库表全部删除,当时吓的要死。结果找到下面的语句恢复到了1个小时之前的数据!很简单。 注意使用管理员登录系统: select * from 表名 as of timestamp sysdate-1/12 //查询两个小时前的某表数据!既然两小时以前的数据都得到了,继续怎么做,知道了吧。。 如果drop了表,怎么办??见下面: drop table 表名; 数据库误删除表之后恢复:( 绝对ok,我就做过这样的事情,汗 )不过要记得删除了哪些表名。 flashback table 表名 to before drop; 2.查询得到当前数据库中锁,以及解锁: 查锁 SELECT /*+ rule */ s.username, decode(l.type,'TM','TABLE LOCK', 'TX','ROW LOCK', NULL) LOCK_LEVEL, o.owner,o.object_name,o.object_type, s.sid,s.serial#,s.terminal,s.machine,s.program,s.osuser FROM v$session s,v$lock l,dba_objects o WHERE l.sid = s.sid AND l.id1 = o.object_id(+) AND s.username is NOT NULL; 解锁 alter system kill session 'sid,serial'; 如果解不了。直接倒os下kill进程kill -9 spid ORA-28000:账户被锁定 因为密码输入错误多次用户自动被锁定. 解决办法:alter user user_name account unlock; 3.关于查询数据库用户,权限的相关语句: 1.查看所有用户: select * from dba_user; select * from all_users; select * from user_users; 2.查看用户系统权限: select * from dba_sys_privs; select * from all_sys_privs; select * from user_sys_privs; 3.查看用户对象权限: 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.查看用户所拥有的角色: select * from dba_role_privs; select * from user_role_privs; 4.几个经常用到的oracle视图:注意表名使用大写.................... 1. 查询oracle中所有用户信息 select * from dba_user; 2. 只查询用户和密码 select username,password from dba_users; 3. 查询当前用户信息 select * from dba_ustats; 4. 查询用户可以访问的视图文本 select * from dba_varrays; 5. 查询数据库中所有视图的文本 select * from dba_views; 6.查询全部索引 select * from user_indexes; 查询全部表格 select * from user_tables; 查询全部约束 select * from user_constraints; 查询全部对象 select * from user_objects; 5.查看当前数据库中正在执行的语句,然后可以继续做很多很多事情,例如查询执行计划等等 (1).查看相关进程在数据库中的会话 Select a.sid,a.serial#,a.program, a.status , substr(a.machine,1,20), a.terminal,b.spid from v$session a, v$process b where a.paddr=b.addr and b.spid = &spid; (2).查看数据库中被锁住的对象和相关会话 select a.sid,a.serial#,a.username,a.program, c.owner, c.object_name from v$session a, v$locked_object b, all_objects c where a.sid=b.session_id and c.object_id = b.object_id; (3).查看相关会话正在执行的SQL select sql_text from v$sqlarea where address = ( select sql_address from v$session where sid = &sid ); 6.查询表的结构:表名大写!! select t.COLUMN_NAME, t.DATA_TYPE, nvl(t.DATA_PRECISION, t.DATA_LENGTH), nvl(T.DATA_SCALE, 0), c.comments from all_tab_columns t, user_col_comments c whEre t.TABLE_NAME = c.table_name and t.COLUMN_NAME = c.column_name and t.TABLE_NAME = UPPER('OM_EMPLOYEE_T') order by t.COLUMN_ID 7.行列互换: 建立一个例子表: CREATE TABLE t_col_row( ID INT, c1 VARCHAR2(10), c2 VARCHAR2(10), c3 VARCHAR2(10)); INSERT INTO t_col_row VALUES (1, 'v11', 'v21', 'v31'); INSERT INTO t_col_row VALUES (2, 'v12', 'v22', NULL); INSERT INTO t_col_row VALUES (3, 'v13', NULL, 'v33'); INSERT INTO t_col_row VALUES (4, NULL, 'v24', 'v34'); INSERT INTO t_col_row VALUES (5, 'v15', NULL, NULL); INSERT INTO t_col_row VALUES (6, NULL, NULL, 'v35'); INSERT INTO t_col_row VALUES (7, NULL, NULL, NULL); COMMIT; 下面的是列转行:创建了一个视图 CREATE view v_row_col AS SELECT id, 'c1' cn, c1 cv FROM t_col_row UNION ALL SELECT id, 'c2' cn, c2 cv FROM t_col_row UNION ALL SELECT id, 'c3' cn, c3 cv FROM t_col_row; 下面是创建了没有空值的一个竖表: CREATE view v_row_col_notnull AS SELECT id, 'c1' cn, c1 cv FROM t_col_row where c1 is not null UNION ALL SELECT id, 'c2' cn, c2 cv FROM t_col_row where c2 is not null UNION ALL SELECT id, 'c3' cn, c3 cv FROM t_col_row where c3 is not null; 8.下面可能是dba经常使用的oracle视图吧。呵呵 1.示例:已知hash_value:3111103299,查询sql语句: select * from v$sqltext where hashvalue='3111103299' order by piece 2.查看消耗资源最多的SQL: SELECT hash_value, executions, buffer_gets, disk_reads, parse_calls FROM V$SQLAREA WHERE buffer_gets > 10000000OR disk_reads > 1000000 ORDERBY buffer_gets + 100 * disk_reads DESC; 3.查看某条SQL语句的资源消耗: SELECT hash_value, buffer_gets, disk_reads, executions, parse_calls FROM V$SQLAREA WHERE hash_Value = 228801498AND address = hextoraw('CBD8E4B0'); 4.查询sql语句的动态执行计划: 首先使用下面的语句找到语句的在执行计划中的address和hash_code SELECT sql_text, address, hash_value FROM v$sql t where (sql_text like '%FUNCTION_T(表名大写!)%') 然后: SELECT operation, options, object_name, cost FROM v$sql_plan WHERE address = 'C00000016BD6D248' AND hash_value = 664376056; 5.查询oracle的版本: select * from v$version; 6.查询数据库的一些参数: select * from v$parameter 7.查找你的session信息 SELECT SID, OSUSER, USERNAME, MACHINE, PROCESS FROM V$SESSION WHERE audsid = userenv('SESSIONID'); 8.当machine已知的情况下查找session SELECT SID, OSUSER, USERNAME, MACHINE, TERMINAL FROM V$SESSION WHERE terminal = 'pts/tl' AND machine = 'rgmdbs1'; 9.查找当前被某个指定session正在运行的sql语句。假设sessionID为100 select b.sql_text from v$session a,v$sqlarea b where a.sql_hashvalue=b.hash_value and a.sid=100 9.树形结构connect by 排序: 查询树形的数据结构,同时对一层里面的数据进行排序 SELECT last_name, employee_id, manager_id, LEVEL FROM employees START WITH employee_id = 100 CONNECT BY PRIOR employee_id = manager_id ORDER SIBLINGS BY last_name; 下面是查询结果 LAST_NAME EMPLOYEE_ID MANAGER_ID LEVEL ------------------------- ----------- ---------- ---------- King 100 1 Cambrault 148 100 2 Bates 172 148 3 Bloom 169 148 3 Fox 170 148 3 Kumar 173 148 3 Ozer 168 148 3 Smith 171 148 3 De Haan 102 100 2 Hunold 103 102 3 Austin 105 103 4 Ernst 104 103 4 Lorentz 107 103 4 Pataballa 106 103 4 Errazuriz 147 100 2 Ande 166 147 3 Banda 167 147 3 10.有时候写多了东西,居然还忘记最基本的sql语法,下面全部写出来,基本的oracle语句都在这里可以找到了。是很基础的语句! 1.在数据字典查询约束的相关信息: SELECT constraint_name, constraint_type,search_condition FROM user_constraints WHERE table_name = 'EMPLOYEES'; //这里的表名都是大写! 2对表结构进行说明: desc Tablename 3查看用户下面有哪些表 select table_name from user_tables; 4查看约束在那个列上建立: SELECT constraint_name, column_name FROM user_cons_columns WHERE table_name = 'EMPLOYEES'; 10结合变量查找相关某个表中约束的相关列名: select constraint_name,column_name from user_cons_columns where table_name = '&tablename' 12查询数据字典看中间的元素: SELECT object_name, object_type FROM user_objects WHERE object_name LIKE 'EMP%' OR object_name LIKE 'DEPT%' 14查询对象类型: SELECT DISTINCT object_type FROM user_objects ; 17改变对象名:(表名,视图,序列) rename emp to emp_newTable 18添加表的注释: COMMENT ON TABLE employees IS 'Employee Information'; 20查看视图结构: describe view_name 23在数据字典中查看视图信息: select viewe_name,text from user_views 25查看数据字典中的序列: select * from user_sequences 33得到所有的时区名字信息: select * from v$timezone_names 34显示对时区‘US/Eastern’的时区偏移量 select TZ_OFFSET('US/Eastern') from DUAL--dual英文意思是‘双重的’ 显示当前会话时区中的当前日期和时间: ALTER SESSION SET NLS_DATE_FORMAT = 'DD-MON-YYYY HH24:MI:SS';--修改显示时间的方式的设置 ALTER SESSION SET TIME_ZONE = '-5:0';--修改时区 SELECT SESSIONTIMEZONE, CURRENT_DATE FROM DUAL;--真正有用的语句! SELECT CURRENT_TIMESTAMP FROM DUAL;--返回的时间是当前日期和时间,含有时区 SELECT CURRENT_TIMESTAMP FROM DUAL;--返回的时间是当前日期和时间,不含有时区!!! 35显示数据库时区和会话时区的值: select datimezone,sessiontimezone from dual; 13普通的建表语句: CREATE TABLE dept (deptno NUMBER(2), dname VARCHAR2(14), loc VARCHAR2(13)); 15使用子查询建立表: CREATE TABLE dept80 AS SELECT employee_id, last_name, salary*12 ANNSAL, hire_date FROM employees WHERE department_id = 80; 6添加列:// alter table EMP add column (dept_id number(7));错误!! alter table EMP add (dept_id number(7)); 7删除一列: alter table emp drop column dept_id; 8添加列名同时和约束: alter table EMP add (dept_id number(7) constraint my_emp_dept_id_fk references dept(ID)); 9改变列://注意约束不能够修改 的!! alter table dept80 modify(last_name varchar2(30));//这里使用的是modify而不是alter! 24增加一行: insert into table_name values(); 5添加主键: alter Table EMP add constraint my_emp_id_pk primary key (ID); 11添加一个有check约束的新列: alter table EMP add (COMMISSION number(2) constraint emp_commission_ck check(commission>0)) 16删除表: drop table emp; 19创建视图: CREATE VIEW empvu80 AS SELECT employee_id, last_name, salary FROM employees WHERE department_id = 80; 21删除视图: drop view view_name 22找到工资最高的5个人。(top-n分析)(行内视图) select rownum,employee_id from (select employee_id,salary from employees order by salary desc) where rownum<5; 26建立同义词: create synonym 同义词名 for 原来的名字 或者 create public synonym 同义词名 for 原来的名字 27建立序列:(注意,这里并没有出现说是哪个表里面的序列!!) CREATE SEQUENCE dept_deptid_seq INCREMENT BY 10 START WITH 120 MAXVALUE 9999 NOCACHE NOCYCLE 28使用序列: insert into dept(ID,NAME) values(DEPT_ID_SEQ.nextval,'Administration'); 29建立索引://默认就是nonunique索引,除非使用了关键字:unique CREATE INDEX emp_last_name_idx ON employees(last_name); 30建立用户:(可能有错,详细查看帮助) create user username(用户名) identified by oracle(密码) default tablespace data01(表空间名//默认存在system表空间里面) quota 10M(设置大小,最大为unlimited) on 表空间名//必须分配配额! 31创建角色:create ROLE manager 赋予角色权限:grant create table,create view to manage 赋予用户角色:grant manager to DENHAAN,KOCHHAR( 两个用户) 32分配权限: GRANT update (department_name, location_id) ON departments TO scott, manager; 回收权限 REVOKE select, insert ON departments FROM scott; 36从时间中提取年,月,日:使用函数extract select extract(year from sysdate) year,extract(month from sysdate), extract(day from sysdate) from dual; 37使用函数得到数月之后的日期:to_yminterval(‘01-02’)表示加上1年2月,不能够到天!! select hire_date,hire_date +to_yminterval('01-02') as hire_date_new from employees where department_id=20 得到多少天之后的日期:直接日期加数字! select hire_date +3 from employees where department_id=20 38一般的时间函数: MONTHS_BETWEEN ('01-SEP-95','11-JAN-94')--两个日期之间的月数,返回一个浮点数 ADD_MONTHS ('11-JAN-94',6)--添加月数 NEXT_DAY ('01-SEP-95','FRIDAY') --下一个星期五的日期 LAST_DAY('01-FEB-95')--当月的最后一天! ROUND(SYSDATE,'MONTH') --四舍五入月 ROUND(SYSDATE ,'YEAR') --四舍五入年 TRUNC(SYSDATE ,'MONTH') --阶段月 TRUNC(SYSDATE ,'YEAR') --截断年 39 group语句:和高级的应用语句: SELECT department_id, job_id, SUM(salary), COUNT(employee_id) FROM employees GROUP BY department_id, job_id ; 使用having进行约束: 1.group by rollup:对n列组合得到n+1种情况 SELECT department_id, job_id, SUM(salary) FROM employees WHERE department_id < 60 GROUP BY ROLLUP(department_id, job_id); 2.group by cube:得到2的n次方种情况 SELECT department_id, job_id, SUM(salary) FROM employees WHERE department_id < 60 GROUP BY CUBE (department_id, job_id) ; 3.使用grouping得到一行中构成列的情况,只是返回1和0:是空的话就返回1,否则返回0(注意不要弄反了!) SELECT department_id DEPTID, job_id JOB, SUM(salary), GROUPING(department_id) GRP_DEPT, GROUPING(job_id) GRP_JOB FROM employees WHERE department_id < 50 GROUP BY ROLLUP(department_id, job_id); 4.grouping sets:根据需要得到制定的组合情况 SELECT department_id, job_id, manager_id,avg(salary) FROM employees GROUP BY GROUPING SETS ((department_id,job_id), (job_id,manager_id)); 40from中使用子查询:返回每个部门中大于改部门平均工资的与员工信息 SELECT a.last_name, a.salary, a.department_id, b.salavg FROM employees a,--下面的地方就是子查询了,主要返回的是一组数据! (SELECT department_id, AVG(salary) salavg FROM employees GROUP BY department_id) b WHERE a.department_id = b.department_id AND a.salary > b.salavg; 41exists语句的使用: SELECT employee_id, last_name, job_id, department_id FROM employees outer--下面的 exists里面的select选择出来的是随便的一个字符或者数字都可以 WHERE EXISTS ( SELECT 'X' FROM employees WHERE manager_id = outer.employee_id); 42厉害的with语句: WITH dept_costs AS (--定义了一个临时的表 SELECT d.department_name, SUM(e.salary) AS dept_total--其间定义了一个临时的列dept_total FROM employees e, departments d WHERE e.department_id = d.department_id GROUP BY d.department_name),/*注意这里有逗号*/ avg_cost AS ( SELECT SUM(dept_total)/COUNT(*) AS dept_avg FROM dept_costs)--这里的第二张临时表里面就引用了前面定义的临时表和之间的列! SELECT * FROM dept_costs WHERE dept_total > (SELECT dept_avg FROM avg_cost) ORDER BY department_name;---最后的查询语句中使用了前面的临时表 43遍历树: SELECT employee_id, last_name, job_id, manager_id FROM employees START WITH employee_id = 101 CONNECT BY PRIOR manager_id = employee_id ;--自底向上的遍历树。 44.更新语句 UPDATE employees SET job_id = 'SA_MAN', salary = salary + 1000, department_id = 120 WHERE first_name||' '||last_name = 'Douglas Grant'; UPDATE TABLE (SELECT projs FROM dept d WHERE d.dno = 123) p SET p.budgets = p.budgets + 1 WHERE p.pno IN (123, 456); 11.导入导出dmp文件: imp 用户名/密码@数据库 ignore=y file=备份文件 log=D:\DBtest\db_bak\imp.log exp system/manager@TEST file=d:\daochu.dmp full=y 12.大对象字段blob:查看blob字段的大小: select dbms_lob.getLength (字段名) from 表名 ; 13.下面收集的是有意思的sql语句,说不定正是你需要的: --创建一个只允许在工作时间访问的视图 create or replace view newviewemp as select * from 表名 where exists(select 1 from dual where sysdate >= to_date(to_char(sysdate, 'yyyy-mm-dd ') || '08:00:00', 'yyyy-mm-dd hh24:mi:ss') and sysdate < to_date(to_char(sysdate, 'yyyy-mm-dd ') || '18:00:00', 'yyyy-mm-dd hh24:mi:ss')) 14.存储过程中执行ddl语句: Create Or Replace Procedure My_Proc As Sqlddl Varchar2(1000); Begin Sqlddl := 'create table MyTable(ID Number(5), Name Varchar2(20))'; Dbms_Output.Put_Line(Sqlddl); Execute Immediate Sqlddl; End;

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