Oracle 實(shí)驗(yàn)8 數(shù)據(jù)庫(kù)備份與恢復(fù).doc

金陵科技學(xué)院實(shí)驗(yàn)報(bào)告實(shí)驗(yàn)8 數(shù)據(jù)庫(kù)備份與恢復(fù)、數(shù)據(jù)閃回技術(shù)和事務(wù)處理一、實(shí)驗(yàn)?zāi)康暮鸵?、理解數(shù)據(jù)庫(kù)備份的意義、數(shù)據(jù)庫(kù)邏輯備份與物理備份的區(qū)別以及各自適用的范圍。2、掌握數(shù)據(jù)庫(kù)邏輯備份與恢復(fù)的方法。3、掌握數(shù)據(jù)庫(kù)物理備份中脫機(jī)備份（冷備份）以及恢復(fù)的方法。4、掌握數(shù)據(jù)庫(kù)物理備份中的聯(lián)機(jī)備份（熱備份）以及恢復(fù)的方法。5、理解Oracle的數(shù)據(jù)庫(kù)閃回技術(shù)適用范圍及局限性，在閃回過(guò)程中基于SCN的閃回技術(shù)和基于時(shí)間戳的閃回技術(shù)。6、掌握使用SQL *Plus命令閃回表、閃回刪除和閃回?cái)?shù)據(jù)庫(kù)的方法7、理解事務(wù)的概念及特性，事務(wù)的提交與回滾，保存點(diǎn)技術(shù)。掌握事務(wù)的完全回退和回退到保存點(diǎn)的方法。二、實(shí)驗(yàn)設(shè)備、環(huán)境設(shè)備：奔騰或奔騰以上計(jì)算機(jī)環(huán)境：WINDOWS 2000 SERVER或WINDOWS 2003 SERVER、ORACLE 10g中文版三、實(shí)驗(yàn)步驟1、分析題意，重點(diǎn)分析題目要求并給出解決方法。2、根據(jù)題目要求啟動(dòng)SQL*Plus、iSQL*Plus、OEM等管理工具。3、按題目要求完成實(shí)際操作任務(wù)，并將相關(guān)文檔資料保存在以自己學(xué)號(hào)命名的文件夾中。4、提交完成的實(shí)驗(yàn)結(jié)果。四、實(shí)驗(yàn)內(nèi)容1、數(shù)據(jù)庫(kù)的邏輯備份與恢復(fù)用EXP命令導(dǎo)出Orcl數(shù)據(jù)庫(kù)中的Departments表。以mybak.dmp文件名存儲(chǔ)在F盤的根目錄下。然后刪除該表中的數(shù)據(jù)。用IMP命令導(dǎo)入Departments表，查看表中的數(shù)據(jù)是否已經(jīng)恢復(fù)。2、數(shù)據(jù)庫(kù)的物理備份（1）冷備份在F盤的oracle目錄下，查找到Orcl子目錄，將該目錄中的數(shù)據(jù)、日志以及控制文件拷貝到E盤的BAK目錄下（需要事先創(chuàng)建好）。然后刪除Orcl子目錄下的部分?jǐn)?shù)據(jù)文件。啟動(dòng)數(shù)據(jù)庫(kù)，觀察其結(jié)果。將E盤的BAK目錄下的相應(yīng)數(shù)據(jù)文件拷回到Orcl子目錄下，啟動(dòng)數(shù)據(jù)庫(kù)，觀察其結(jié)果。（2）聯(lián)機(jī)備份與恢復(fù)首先將數(shù)據(jù)庫(kù)改變?yōu)闅w檔模式。將MYTS表空間進(jìn)行備份。將MYTS表空間中的的數(shù)據(jù)文件例如MYTS01拷貝到F:BACKUP目錄下。將當(dāng)前的聯(lián)機(jī)日志進(jìn)行歸檔和切換。（使用ALTER SYSTEM archive log CURRENT 命令和ALTER SYSTEM SWITCH LOG，F(xiàn)ILE）關(guān)閉數(shù)據(jù)庫(kù)。將MYTS01數(shù)據(jù)文件刪除。然后再啟動(dòng)數(shù)據(jù)庫(kù)，觀察出錯(cuò)信息。將錯(cuò)的文件脫機(jī)并刪除掉。打開(kāi)數(shù)據(jù)庫(kù)。此時(shí)將備份的文件拷貝到原來(lái)的路徑下?；謴?fù)出錯(cuò)的文件，將該文件設(shè)置為聯(lián)機(jī)。在察看結(jié)果，看是否已經(jīng)恢復(fù)。3、數(shù)據(jù)庫(kù)的閃回技術(shù)（1）閃回查詢（2）閃回表（注意：閃回表事先要進(jìn)行允許行遷移的準(zhǔn)備）（3）閃回刪除4、事務(wù)管理（1）回退全部事務(wù)（2）利用保存點(diǎn)技術(shù)將事務(wù)回退的保存點(diǎn)處。五、問(wèn)題解答及實(shí)驗(yàn)結(jié)果1、數(shù)據(jù)庫(kù)的邏輯備份與恢復(fù)（1）導(dǎo)出SQL select * 2 from departments;DEP DEPARTMENTNAME NOTE- - -1 財(cái)務(wù)部2 人力資源部3 經(jīng)理辦公室4 研發(fā)部5 市場(chǎng)部SQL drop table departments;表已刪除。SQL select * 2 from departments;from departments *第 2 行出現(xiàn)錯(cuò)誤:ORA-00942: 表或視圖不存在（2）導(dǎo)入SQL select * 2 from departments;DEP DEPARTMENTNAME NOTE- - -1 財(cái)務(wù)部2 人力資源部3 經(jīng)理辦公室4 研發(fā)部5 市場(chǎng)部2、物理備份（1）冷備份-查詢控制文件所在的目錄set pagesize 30col name for a60select name from v$controlfile;NAME-F:ORACLEPRODUCT10.2.0ORADATAORCLCONTROL01.CTLF:ORACLEPRODUCT10.2.0ORADATAORCLCONTROL02.CTLF:ORACLEPRODUCT10.2.0ORADATAORCLCONTROL03.CTL-查詢?nèi)罩疚募诘哪夸沜ol member for a60select member from v$logfile;MEMBER-F:ORACLEPRODUCT10.2.0ORADATAORCLREDO03.LOGF:ORACLEPRODUCT10.2.0ORADATAORCLREDO02.LOGF:ORACLEPRODUCT10.2.0ORADATAORCLREDO01.LOG-查詢所有數(shù)據(jù)文件所在的目錄和文件名col file_name for a60set linesize 120FILE_NAME TABLESPACE_NAME- -F:ORACLEPRODUCT10.2.0ORADATAORCLUSERS01.DBF USERSF:ORACLEPRODUCT10.2.0ORADATAORCLSYSAUX01.DBF SYSAUXF:ORACLEPRODUCT10.2.0ORADATAORCLUNDOTBS01.DBF UNDOTBS1F:ORACLEPRODUCT10.2.0ORADATAORCLSYSTEM01.DBF SYSTEMF:ORACLEPRODUCT10.2.0ORADATAORCLEXAMPLE01.DBF EXAMPLEF:DISK2ORCLPIONEER_DATA.DBF PIONEER_DATAF:DISK4ORCLPIONEER_INDX.DBF PIONEER_INDX-查詢參數(shù)文件所在的目錄show parameter pfileNAME TYPE VALUE- - - -spfile string F:ORACLEPRODUCT10.2.0DB_1 DBSSPFILEORCL.ORA-創(chuàng)建備份文件存放的目錄SQLHOST -該命令從sqlplus窗口轉(zhuǎn)換到dos窗口f:md backup f:cd backupf:backupmd databasef:backupmd dbsf:backupmd disk2f:backupmd disk4f:backupdir-創(chuàng)建存儲(chǔ)腳本文件的目錄f:oraclemd mgt-編寫冷備份腳本文件：CONNECT SYS/ORCL123 AS SYSDBASHUTDOWN IMMEDIATEHOST COPY F:ORACLEPRODUCT10.2.0ORADATAORCL*.* F:backupHOST COPY F:ORACLEPRODUCT10.2.0db_1dbsSPFILEORCL.ORA F:backupdbsHOST COPY F:ORACLEPRODUCT10.2.0db_1databasepwdorcl.ora F:dackupdatabaseHOST COPY F:disk2orclPINOEER_DATA.DBF F:backupdisk2HOST COPY F:disk4orclPINOEER_INDX.DBF F:backupdisk4STARTUP將以上腳本保存在f:oraclemgtcoolbak.sql-冷備份的實(shí)施，運(yùn)行coolbak.sqlSQLF:oraclemgtcoolbak-查看backup目錄下的所有文件SQLHOSTF:oracleproduct10.2.0db_1bin cd f:backupf:backupdir模擬數(shù)據(jù)損害，刪除數(shù)據(jù)文件后，用下面的命令進(jìn)行恢復(fù)。SQLconnect sys/orcl123 as sysdbaSQLshutdown immediateSQLHOST COPY F:backup*.* F:oracleproduct10.2.0oradataorclSQLHOST COPY F:backupdbsSPFILEORCL.ORA F:oracleproduct10.2.0dbackup_1dbsSQLHOST COPY F:backupdatabasePWDORCL.ORA F:oracleproduct10.2.0db_1databaseSQLHOST COPY F:backupdisk2PIONEER_DATA.DBF F:DISK2ORCLSQLHOST COPY F:backupdisk4PIONEER_INEX.DBF F:DISK4ORCLSQLSTARTUP（2）熱備份SQL archive log list數(shù)據(jù)庫(kù)日志模式 非存檔模式自動(dòng)存檔 禁用存檔終點(diǎn) USE_DB_RECOVERY_FILE_DEST最早的聯(lián)機(jī)日志序列 11當(dāng)前日志序列 13數(shù)據(jù)庫(kù)已經(jīng)關(guān)閉。已經(jīng)卸載數(shù)據(jù)庫(kù)。ORACLE 例程已經(jīng)關(guān)閉。SQL startup mountORACLE 例程已經(jīng)啟動(dòng)。Total System Global Area 209715200 bytesFixed Size 1248140 bytesVariable Size 88081524 bytesDatabase Buffers 117440512 bytesRedo Buffers 2945024 bytes數(shù)據(jù)庫(kù)裝載完畢。SQL alter database archivelog;數(shù)據(jù)庫(kù)已更改。SQL alter database open;數(shù)據(jù)庫(kù)已更改。SQL archive log list數(shù)據(jù)庫(kù)日志模式 存檔模式自動(dòng)存檔 啟用存檔終點(diǎn) USE_DB_RECOVERY_FILE_DEST最早的聯(lián)機(jī)日志序列 31下一個(gè)存檔日志序列 33當(dāng)前日志序列 33SQL alter tablespace MYTS begin backup;表空間已更改。SQL HOST COPY F:ORACLEPRODUCT10.2.0ORADATAORCLMYTS01 F:BACKUP;SQL ALTER TABLESPACE MYTS END BACKUP;表空間已更改。SQL SHUTDOWN IMMEDIATE;數(shù)據(jù)庫(kù)已經(jīng)關(guān)閉。已經(jīng)卸載數(shù)據(jù)庫(kù)。ORACLE 例程已經(jīng)關(guān)閉。模擬數(shù)據(jù)庫(kù)損壞，刪除MYTS01數(shù)據(jù)文件。SQL STARTUPORACLE 例程已經(jīng)啟動(dòng)。Total System Global Area 209715200 bytesFixed Size 1248140 bytesVariable Size 130024564 bytesDatabase Buffers 75497472 bytesRedo Buffers 2945024 bytes數(shù)據(jù)庫(kù)裝載完畢。ORA-01157: 無(wú)法標(biāo)識(shí)/鎖定數(shù)據(jù)文件 8 - 請(qǐng)參閱 DBWR 跟蹤文件ORA-01110: 數(shù)據(jù)文件 8: F:ORACLEPRODUCT10.2.0ORADATAORCLMYTS01SQL alter database datafile 8 offline; 數(shù)據(jù)庫(kù)已更改。SQL alter database open;數(shù)據(jù)庫(kù)已更改。SQL select file#,status from v$datafile; FILE# STATUS- - 1 SYSTEM 2 ONLINE 3 ONLINE 4 ONLINE 5 ONLINE 6 ONLINE 7 ONLINE 8 OFFLINE已選擇8行。SQL col error for a20SQL select * from v$recover_file; FILE# ONLINE ONLINE_ ERROR CHANGE# TIME- - - - - - - 8 OFFLINE OFFLINE FILE NOT FOUND 0SQLHOST COPY F:BACKUPMYTS01 F:ORACLEPRODUCT10.2.0ORADATAORCLSQL RECOVER DATAFILE 8完成介質(zhì)恢復(fù)。SQL ALTER TABLESPACE MYTS ONLINE;表空間已更改。SQL SELECT FILE#,STATUS FROM V$DATAFILE; FILE# STATUS- - 1 SYSTEM 2 ONLINE 3 ONLINE 4 ONLINE 5 ONLINE 6 ONLINE 7 ONLINE 8 ONLINE已選擇8行。SQL CONNECT ADMIN/ADMIN123已連接。SQL SELECT COUNT(*) 2 FROM SALES; COUNT(*)- 918843SQL SELECT COUNT(*) 2 FROM customers; COUNT(*)- 555003、數(shù)據(jù)庫(kù)閃回技術(shù)（1）閃回查詢SQL CONNECT SYS/ORCL123 AS SYSDBA已連接。SQL grant execute on dbms_flashback to scott;授權(quán)成功。SQL SELECT TO_CHAR(sysdate,yyyy-mm-dd hh24:mi:ss)current_time from dual;CURRENT_TIME-2012-06-05 17:08:53SQL conn scott/tiger;已連接。SQL SELECT ENAME,SAL FROM EMP WHERE EMPNO=7788;ENAME SAL- -SCOTT 3000SQL VARIABLE scn_now NUMBERSQL EXECUTE :scn_now :=dbms_flashback.get_system_change_number; -獲取SCN的值。PL/SQL 過(guò)程已成功完成。SQL PRINT :scn_now SCN_NOW- 1297964SQL SET TIME ON17:10:50 SQL EXECUTE dbms_flashback.disable; PL/SQL 過(guò)程已成功完成。17:11:06 SQL UPDATE EMP SET SAL=4000 WHERE EMPNO=7788;已更新 1 行。17:11:28 SQL CONN SCOTT/TIGER已連接。17:11:49 SQL EXECUTE :scn_now:=dbms_flashback.get_system_change_number;PL/SQL 過(guò)程已成功完成。17:12:16 SQL PRINT :SCN_NOW SCN_NOW- 129806117:12:33 SQL EXECUT dbms_flashback.enable_at_system_change_number(:scn_now);PL/SQL 過(guò)程已成功完成。17:13:24 SQL SELECT ENAME,SAL FROM EMP WHERE EMPNO=7788;ENAME SAL- -SCOTT 400017:13:48 SQL execute dbms_flashback.disable;PL/SQL 過(guò)程已成功完成。17:14:14 SQL execute dbms_flashback.enable_at_system_change_number(1297964);PL/SQL 過(guò)程已成功完成。17:15:13 SQL SELECT EMPNO,SAL FROM EMP WHERE EMPNO=7788; EMPNO SAL- - 7788 300017:15:34 SQL EXECUTE dbms_flashback.disable;PL/SQL 過(guò)程已成功完成。17:16:07 SQL UPDATE EMP SET SAL=4500 WHERE EMPNO=7788;已更新 1 行。17:16:27 SQL COMMIT;提交完成。17:17:01SQLEXECUTE dbms_flashback.enable_at_time( to_date(2012-06-05 17:13:48,yyyy-mm-dd hh24:mi:ss);PL/SQL 過(guò)程已成功完成。17:19:09 SQL SELECT EMPNO,SAL FROM EMP WHERE EMPNO=7788; EMPNO SAL- - 7788 400017:19:49 SQL EXECUTE dbms_flashback.disable;PL/SQL 過(guò)程已成功完成。17:20:16 SQL EXECUTE dbms_flashback.disable;PL/SQL 過(guò)程已成功完成。17:20:34 SQL SET TIME OFF;SQL（2）閃回表一、創(chuàng)建閃回表的測(cè)試條件（創(chuàng)建一個(gè)表空間、一個(gè)用戶，并給用戶授權(quán)）SQL CREATE TABLESPACE loc_tbs01 2 DATAFILE e:loc_tas01_1.dbf SIZE 5M 3 EXTENT MANAGEMENT LOCAL;表空間已創(chuàng)建。SQL CREATE USER myuser1 IDENTIFIED BY user1pswd 2 DEFAULT TABLESPACE loc_tbs01 3 TEMPORARY TABLESPACE temp 4 QUOTA 2M ON loc_tbs01;用戶已創(chuàng)建。SQL GRANT connect,resource TO myuser1;授權(quán)成功。SQL GRANT execute ON dbms_flashback to myuser1;授權(quán)成功。二、模擬用戶操作SQL connect myuser1/user1pswd;已連接。 CREATE TABLE Department (DeptNo CHAR(2) NOT NULL, Name VARCHAR2(20) NOT NULL, Address VARCHAR2(30), CONSTRAINT PK_DepNO PRIMARY KEY (DeptNo) VALIDATE);表已創(chuàng)建。SQL CREATE TABLE Student (StuNo VARCHAR2(12) NOT NULL, Name VARCHAR2(15) NOT NULL, Sex CHAR(1), DeptNo CHAR(2), CONSTRAINT PK_StuNo PRIMARY KEY (StuNo) VALIDATE, CONSTRAINT FK_DeptNO FOREIGN KEY (DeptNo) REFERENCES Department(DeptNo) VALIDATE);表已創(chuàng)建。SQL COMMIT;提交完成。SQL CREATE UNIQUE INDEX idx_Department ON Department(Name);索引已創(chuàng)建。 SQL CREATE INDEX idx_Student_name ON Student(Name);索引已創(chuàng)建。SQL SELECT index_name,table_name,uniqueness FROM user_indexes;INDEX_NAME TABLE_NAME UNIQUENES- - -PK_DEPNO DEPARTMENT UNIQUEIDX_DEPARTMENT DEPARTMENT UNIQUEPK_STUNO STUDENT UNIQUEIDX_STUDENT_NAME STUDENT NONUNIQUESQL COMMIT;-注意：先往Demartment表中插入數(shù)據(jù)，然后再向Student表插入數(shù)據(jù)，想一下為什么？SQL INSERT INTO Department VALUES(01,計(jì)算機(jī)系,1號(hào)樓);INSERT INTO Department VALUES(02,自動(dòng)控制系,2號(hào)樓);INSERT INTO Department VALUES(03,電子技術(shù)系,3號(hào)樓);SQLINSERT INTO Student VALUES(20060302001,jack,1,03);INSERT INTO Student VALUES(20060302002,smith,1,03);INSERT INTO Student VALUES(20060302003,Iucy,0,03);SQL COMMIT;三、采用基于時(shí)間點(diǎn)閃回表SQL VARIABLE scn_now numberSQL EXECUTE :scn_now :=dbms_flashback.get_system_change_number; -獲取SCNPL/SQL 過(guò)程已成功完成。SQL PRINT scn_now SCN_NOW- 1299435SQL ALTER TABLE Department ENABLE ROW MOVEMENT; 表已更改。SQL ALTER TABLE Student ENABLE ROW MOVEMENT;表已更改。SQL SELECT TO_CHAR(sysdate,yyyy-mm-dd hh24:mi:ss) CURRENT_TIME FROM dual;CURRENT_TIME-2012-06-05 17:42:41SQL TRUNCATE TABLE Student;表被截?cái)唷QL DROP INDEX idx_Department;索引已刪除。SQL DELETE FROM Department;已刪除3行。SQL COMMIT;提交完成。SQL FLASHBACK TABLE Student TO TIMESTAMP to_timestamp(2012-06-05 17:42:41,yyyy-mm-dd hh24:mi:ss);FLASHBACK TABLE Student TO TIMESTAMP to_timestamp(2012-06-05 17:42:41,yyyy-mm-dd hh24:mi:ss) *第 1 行出現(xiàn)錯(cuò)誤:ORA-01466: 無(wú)法讀取數(shù)據(jù) - 表定義已更改 -用TRUNCATE 命令截?cái)嗟谋聿荒荛W回SQL FLASHBACK TABLE Department TO TIMESTAMP to_timestamp(2012-06-05 17:42:41,yyyy-mm-dd hh24:mi:ss);閃回完成。 -閃回了Department表中的數(shù)據(jù)SQL COMMIT;提交完成。SQL SELECT * FROM Student;未選定行SQL SELECT * FROM Department;DE NAME ADDRESS- - -01 計(jì)算機(jī)系 1號(hào)樓02 自動(dòng)控制系 2號(hào)樓03 電子技術(shù)系 3號(hào)樓SQL SELECT index_name,table_name,uniqueness FROM user_indexes;INDEX_NAME TABLE_NAME UNIQUENES- - -PK_STUNO STUDENT UNIQUEIDX_STUDENT_NAME STUDENT NONUNIQUEPK_DEPNO DEPARTMENT UNIQUE-雖然閃回了Department表中的數(shù)據(jù)但不能閃回單獨(dú)刪除的索引。四、禁用行移動(dòng)功能SQL ALTER TABLE Department ENABLE ROW MOVEMENT; 表已更改。SQL ALTER TABLE Student ENABLE ROW MOVEMENT; 表已更改。（3）閃回刪除一、將測(cè)試環(huán)境恢復(fù)到初始狀態(tài)-用DROP TABLE TABLE_name CASCADE CONSTRAINT 命令刪除表及其索引然后重新創(chuàng)建SQL DROP TABLE Student CASCADE CONSTRAINT;表已刪除。SQL DROP TABLE Department CASCADE CONSTRAINT;表已刪除。-重新創(chuàng)建表 CREATE TABLE Department (DeptNo CHAR(2) NOT NULL, Name VARCHAR2(20) NOT NULL, Address VARCHAR2(30), CONSTRAINT PK_DepNO PRIMARY KEY (DeptNo) VALIDATE);表已創(chuàng)建。 CREATE TABLE Student (StuNo VARCHAR2(12) NOT NULL, Name VARCHAR2(15) NOT NULL, Sex CHAR(1), DeptNo CHAR(2), CONSTRAINT PK_StuNo PRIMARY KEY (StuNo) VALIDATE, CONSTRAINT FK_DeptNO2 FOREIGN KEY (DeptNo) REFERENCES Department(DeptNo) VALIDATE);表已創(chuàng)建。SQL COMMIT;提交完成。SQL CREATE UNIQUE INDEX idx_Department ON Department(Name);索引已創(chuàng)建。SQL CREATE INDEX idx_Student_name ON Student(Name);索引已創(chuàng)建。-向Department表插入數(shù)據(jù)INSERT INTO Department VALUES(01,計(jì)算機(jī)系,1號(hào)樓);INSERT INTO Department VALUES(02,自動(dòng)控制系,2號(hào)樓);INSERT INTO Department VALUES(03,電子技術(shù)系,3號(hào)樓);-向Student表插入數(shù)據(jù)INSERT INTO StudentVALUES(20090601001,jack,1,03);INSERT INTO StudentVALUES(20090601002,smith,1,03);INSERT INTO StudentVALUES(20090601003,Iucy,0,03);二、創(chuàng)建一個(gè)觸發(fā)器 CREATE OR REPLACE TRIGGER tr_Student_ActionTime BEFORE insert OR update OR delete ON Student BEGIN IF (TO_CHAR(sysdate,DAY) IN (星期六,星期天) OR (TO_CHAR(sysdate,HH24) NOT BETWEEN 8 AND 18 ) THEN RAISE_APPLICATION_ERROR(-20001,不是上班時(shí)間，不能修改Student表); END IF;END;/觸發(fā)器已創(chuàng)建三、清除回收站，查詢刪除表之前的表、索引、觸發(fā)器的信息。-清空回收站內(nèi)容SQL PURGE RECYCLEBIN;回收站已清空。SQL SELECT table_name,tablespace_name FROM user_tables;TABLE_NAME TABLESPACE_NAME- -STUDENT LOC_TBS01DEPARTMENT LOC_TBS01SYS_TEMP_FBTSQL SELECT index_name,table_name,uniqueness FROM user_indexes ORDER BY table_name;INDEX_NAME TABLE_NAME UNIQUENES- - -PK_DEPNO DEPARTMENT UNIQUEIDX_DEPARTMENT DEPARTMENT UNIQUEPK_STUNO STUDENT UNIQUEIDX_STUDENT_NAME STUDENT NONUNIQUESQL SELECT trigger_name,trigger_type,table_name FROM user_triggers;TRIGGER_NAME TRIGGER_TYPE TABLE_NAME- - -TR_STUDENT_ACTIONTIME BEFORE STATEMENT STUDENT四、模擬用戶進(jìn)行數(shù)據(jù)庫(kù)操作，刪除Student表和Department表SQL DROP TABLE Student CASCADE CONSTRAINT;表已刪除。SQL DROP TABLE Department CASCADE CONSTRAINT;表已刪除。五、查看刪除表以后的效果SQL desc user_recyclebin; 名稱 是否為空? 類型 - - - OBJECT_NAME NOT NULL VARCHAR2(30) ORIGINAL_NAME VARCHAR2(32) OPERATION VARCHAR2(9) TYPE VARCHAR2(25) TS_NAME VARCHAR2(30) CREATETIME VARCHAR