oracle9i

######### 建立資料庫----look $ORACLE_HOME/rdbms/admin/buildall.sql #############

create database db01
maxlogfiles 10
maxdatafiles 1024
maxinstances 2
logfile
        GROUP 1 ('/u01/oradata/db01/log_01_db01.rdo') SIZE 15M,
        GROUP 2 ('/u01/oradata/db01/log_02_db01.rdo') SIZE 15M,
        GROUP 3 ('/u01/oradata/db01/log_03_db01.rdo') SIZE 15M,
   datafile 'u01/oradata/db01/system_01_db01.dbf') SIZE 100M,
   undo tablespace UNDO
      datafile '/u01/oradata/db01/undo_01_db01.dbf' SIZE 40M
   default temporary tablespace TEMP
      tempfile '/u01/oradata/db01/temp_01_db01.dbf' SIZE 20M
      extent management local uniform. size 128k
   character set AL32UTE8
   national character set AL16UTF16
   set time_zone='America/New_York';

############### 資料字典 ##########

set wrap off

select * from v$dba_users;

grant select on table_name to user/rule;

select * from user_tables;

select * from all_tables;

select * from dba_tables;

revoke dba from user_name;

shutdown immediate

startup nomount

select * from v$instance;

select * from v$sga;

select * from v$tablespace;

alter session set nls_language=american;

alter database mount;

select * from v$database;

alter database open;

desc dictionary

select * from dict;

desc v$fixed_table;

select * from v$fixed_table;

set oracle_sid=foxconn

select * from dba_objects;

set serveroutput on

execute dbms_output.put_line('sfasd');

############# 控制檔案 ###########

select * from v$database;

select * from v$tablespace;

select * from v$logfile;

select * from v$log;

select * from v$backup;

/*備份使用者表空間*/
alter tablespace users begin backup;

select * from v$archived_log;

select * from v$controlfile;

alter system set control_files='$ORACLE_HOME/oradata/u01/ctrl01.ctl',
'$ORACLE_HOME/oradata/u01/ctrl02.ctl' scope=spfile;

cp $ORACLE_HOME/oradata/u01/ctrl01.ctl $ORACLE_HOME/oradata/u01/ctrl02.ctl

startup pfile='../initSID.ora'

select * from v$parameter where name like 'control%' ;

show parameter control;

select * from v$controlfile_record_section;

select * from v$tempfile;

/*備份控制檔案*/
alter database backup controlfile to '../filepath/control.bak';

/*備份控制檔案，並將二進位制控制檔案變為了asc 的文字檔案*/
alter database backup controlfile to trace;

############### redo log ##############

archive log list;

alter system archive log start;--啟動自動存檔

alter system switch logfile;--強行進行一次日誌switch

alter system checkpoint;--強制進行一次checkpoint

alter tablspace users begin backup;

alter tablespace offline;

/*checkpoint 同步頻率引數FAST_START_MTTR_TARGET,同步頻率越高，系統恢復所需時間越短*/
show parameter fast;

show parameter log_checkpoint;

/*加入一個日誌組*/
alter database add logfile group 3 ('/$ORACLE_HOME/oracle/ora_log_file6.rdo' size 10M);

/*加入日誌組的一個成員*/
alter database add logfile member '/$ORACLE_HOME/oracle/ora_log_file6.rdo' to group 3;

/*刪除日誌組:當前日誌組不能刪；活動的日誌組不能刪；非歸檔的日誌組不能刪*/
alter database drop logfile group 3;

/*刪除日誌組中的某個成員，但每個組的最後一個成員不能被刪除*/
alter databse drop logfile member '$ORACLE_HOME/oracle/ora_log_file6.rdo';

/*清除線上日誌*/
alter database clear logfile '$ORACLE_HOME/oracle/ora_log_file6.rdo';

alter database clear logfile group 3;

/*清除非歸檔日誌*/
alter database clear unarchived logfile group 3;

/*重新命名日誌檔案*/
alter database rename file '$ORACLE_HOME/oracle/ora_log_file6.rdo' to '$ORACLE_HOME/oracle/ora_log_file6a.rdo';

show parameter db_create;

alter system set db_create_online_log_dest_1='path_name';

select * from v$log;

select * from v$logfile;

/*資料庫歸檔模式到非歸檔模式的互換,要啟動到mount狀態下才能改變;startup mount;然後再開啟資料庫.*/
alter database noarchivelog/archivelog;

achive log start;---啟動自動歸檔

alter system archive all;－－手工歸檔所有日誌檔案

select * from v$archived_log;

show parameter log_archive;

###### 分析日誌檔案logmnr ##############

1) 在init.ora中set utl_file_dir 引數
2) 重新啟動oracle
3) create 目錄檔案
desc dbms_logmnr_d;
dbms_logmnr_d.build;
4) 加入日誌檔案 add/remove log file
dhms_logmnr.add_logfile
dbms_logmnr.removefile
5) start logmnr
dbms_logmnr.start_logmnr
6) 分析出來的內容查詢  v$logmnr_content --sqlredo/sqlundo

實踐：

desc dbms_logmnr_d;

/*對資料表做一些操作，為恢復操作做準備*/
update 表 set qty=10 where stor_id=6380;

delete 表 where stor_id=7066;
/***********************************/
                                               utl_file_dir的路徑
execute dbms_logmnr_d.build('foxdict.ora','$ORACLE_HOME/oracle/admin/fox/cdump');

execute dbms_logmnr.add_logfile('$ORACLE_HOME/oracle/ora_log_file6.log',dbms_logmnr.newfile);

execute dbms_logmnr.start_logmnr(dictfilename=>;'$ORACLE_HOME/oracle/admin/fox/cdump/foxdict.ora');

######### tablespace ##############

select * form. v$tablespace;

select * from v$datafile;

/*表空間和資料檔案的對應關係*/
select t1.name,t2.name from v$tablespace t1,v$datafile t2 where t1.ts#=t2.ts#;

alter tablespace users add datafile 'path' size 10M;

select * from dba_rollback_segs;

/*限制使用者在某表空間的使用限額*/
alter user user_name quota 10m on tablespace_name;

create tablespace xxx [datafile 'path_name/datafile_name'] [size xxx] [extent management local/dictionary] [default storage(xxx)];

exmple: create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M AUTOEXTEND ON NEXT 5M MAXSIZE 200M;
        create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M extent management dictionary default storage(initial 100k next 100k pctincrease 10) offline;
        /*9i以後，oracle建議使用local管理，而不使用dictionary管理，因為local採用bitmap管理表空間 ，不會產生系統表空間的自願爭用;*/
        create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M extent management local uniform. size 1m;
        create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M extent management local autoallocate;
        /*在建立表空間時，設定表空間內的段空間管理模式，這裡用的是自動管理*/
        create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M extent management local uniform. size 1m segment space management auto;

alter tablespace userdata mininum extent 10;

alter tablespace userdata default storage(initial 1m next 1m pctincrease 20);

/*undo tablespace(不能被用在字典管理模下) */
create undo tablespace undo1 datafile '$ORACLE_HOME/oradata/undo101.dbf' size 40M extent management local;

show parameter undo;

/*temporary tablespace*/
create temporary tablespace userdata tempfile '$ORACLE_HOME/oradata/undo101.dbf' size 10m extent management local;

/*設定資料庫預設的臨時表空間*/
alter database default temporary tablespace tablespace_name;

/*系統/臨時/線上的undo表空間不能被offline*/
alter tablespace tablespace_name offline/online;

alter tablespace tablespace_name read only;

/*重新命名使用者表空間*/
alter tablespace tablespace_name rename datafile '$ORACLE_HOME/oradata/undo101.dbf' to '$ORACLE_HOME/oradata/undo102.dbf';

/*重新命名系統表空間 ,但在重新命名前必須將資料庫shutdown,並重啟到mount狀態*/
alter database rename file '$ORACLE_HOME/oradata/system01.dbf' to '$ORACLE_HOME/oradata/system02.dbf';

drop tablespace userdata including contents and datafiles;---drop tablespce

/*resize tablespace,autoextend datafile space*/
alter database datafile '$ORACLE_HOME/oradata/undo102.dbf' autoextend on next 10m maxsize 500M;

/*resize datafile*/
alter database datafile '$ORACLE_HOME/oradata/undo102.dbf' resize 50m;

/*給表空間擴充套件空間*/
alter tablespace userdata add datafile '$ORACLE_HOME/oradata/undo102.dbf' size 10m;

/*將表空間設定成OMF狀態*/
alter system set db_create_file_dest='$ORACLE_HOME/oradata';

create tablespace userdata;---use OMF status to create tablespace;

drop tablespace userdata;---user OMF status to drop tablespace;

select * from dba_tablespace/v$tablespace/dba_data_files;

/*將表的某分割槽移動到另一個表空間*/
alter table table_name move partition partition_name tablespace tablespace_name;

###### ORACLE storage structure and relationships #########

/*手工分配表空間段的分割槽(extend)大小*/
alter table kong.test12 allocate extent(size 1m datafile '$ORACLE_HOME/oradata/undo102.dbf');

alter table kong.test12 deallocate unused; ---釋放表中沒有用到的分割槽

show parameter db;

alter system set db_8k_cache_size=10m;  ---配置8k塊的記憶體空間塊引數

select * from dba_extents/dba_segments/data_tablespace;

select * from dba_free_space/dba_data_file/data_tablespace;

/*資料物件所佔用的位元組數*/
select sum(bytes) from dba_extents where nwer='kong' and segment_name ='table_name';

############ UNDO Data ################

show parameter undo;

alter tablespace users offline normal;

alter tablespace users offline immediate;

recover datafile '$ORACLE_HOME/oradata/undo102.dbf';

alter tablespace users online ;

select * from dba_rollback_segs;

alter system set undo_tablespace=undotbs1;

/*忽略回滾段的錯誤提示*/
alter system set undo_suppress_errors=true;

/*在自動管理模式下,不會真正建立rbs1;在手工管理模式則可以建立,且是私有回滾段*/
create rollback segment rbs1 tablespace undotbs;

desc dbms_flashback;

/*在提交了修改的資料後,9i提供了舊資料的回閃操作,將修改前的資料只讀給使用者看,但這部分資料不會又恢復在表中,而是舊資料的一個對映*/
execute dbms_flashback.enable_at_time('26-JAN-04:12:17:00 pm');

execute dbms_flashback.disable;

/*回滾段的統計資訊*/
select end_time,begin_time,undoblks from v$undostat;

/*undo表空間的大小計算公式:  UndoSpace=[UR * (UPS * DBS)] + (DBS * 24)
                            UR :UNDO_RETENTION 保留的時間(秒)
                            UPS :每秒的回滾資料塊
                            DBS:系統EXTENT和FILE SIZE(也就是db_block_size)*/

select * from dba_rollback_segs/v$rollname/v$rollstat/v$undostat/v$session/v$transaction;

show parameter transactions;

show parameter rollback;

/*在手工管理模式下,建立公共的回滾段*/
create public rollback segment prbs1 tablespace undotbs;

alter rollback segment rbs1 online;----在手工管理模式

/*在手工管理模式中,initSID.ora中指定 undo_management=manual 、rollback_segment=('rbs1','rbs2',...)、
  transactions=100 、transactions_per_rollback_segment=10
  然後 shutdown immediate ,startup pfile=....\???.ora */

########## Managing Tables ###########

/*char type maxlen=2000;varchar2 type maxlen=4000 bytes
  rowid 是18位的64進位制字串 (10個bytes  80 bits)
  rowid組成:  object#(物件號)--32bits,6位
              rfile#(相對檔案號)--10bits,3位
              block#(塊號)--22bits,6位
              row#(行號)--16bits,3位
  64進位制: A-Z,a-z,0-9,/,+  共64個符號
  
  dbms_rowid 包中的函式可以提供對rowid的解釋*/

select rowid,dbms_rowid.rowid_block_number(rowid),dbms_rowid.rowid_row_number(rowid) from table_name;

create table test2
(
id int,
lname varchar2(20) not null,
fname varchar2(20) constraint ck_1 check(fname like 'k%'),
empdate date default sysdate)
) tablespace tablespace_name;


create global temporary table test2 on commit delete/preserve rows as select * from kong.authors;

create table user.table(...) tablespace tablespace_name storage(...) pctfree10 pctused 40;

alter table user.tablename pctfree 20 pctused 50 storage(...);---changing table storage

/*手工分配分割槽,分配的資料檔案必須是表所在表空間內的資料檔案*/
alter table user.table_name allocate extent(size 500k datafile '...');

/*釋放表中沒有用到的空間*/
alter table table_name deallocate unused;

alter table table_name deallocate unused keep 8k;

/*將非分割槽表的表空間搬到新的表空間,在移動表空間後，原表中的索引物件將會不可用，必須重建*/
alter table user.table_name move tablespace new_tablespace_name;

create index index_name on user.table_name(column_name) tablespace users;

alter index index_name rebuild;

drop table table_name [CASCADE CONSTRAINTS];

alter table user.table_name drop column col_name [CASCADE CONSTRAINTS CHECKPOINT 1000];---drop column

/*給表中不用的列做標記*/
alter table user.table_name set unused column comments CASCADE CONSTRAINTS;

/*drop表中不用的做了標記列*/
alter table user.table_name drop unused columns checkpoint 1000;

/*當在drop col是出現異常，使用CONTINUE，防止重刪前面的column*/
ALTER TABLE USER.TABLE_NAME DROP COLUMNS CONTINUE CHECKPOINT 1000;

select * from dba_tables/dba_objects;

######## managing indexes ##########

/*create index*/
example:
         /*建立一般索引*/
         create index index_name on table_name(column_name) tablespace tablespace_name;
         /*建立點陣圖索引*/
         create bitmap index index_name on table_name(column_name1,column_name2) tablespace tablespace_name;
         /*索引中不能用pctused*/
         create [bitmap] index index_name on table_name(column_name) tablespace tablespace_name pctfree 20 storage(inital 100k next 100k) ;
         /*大資料量的索引最好不要做日誌*/
         create [bitmap] index index_name table_name(column_name1,column_name2) tablespace_name pctfree 20 storage(inital 100k next 100k) nologging;
         /*建立反轉索引*/
         create index index_name on table_name(column_name) reverse;
         /*建立函式索引*/
         create index index_name on table_name(function_name(column_name)) tablespace tablespace_name;
         /*建表時建立約束條件*/
         create table user.table_name(column_name number(7) constraint constraint_name primary key deferrable using index storage(initial 100k next 100k) tablespace tablespace_name,column_name2 varchar2(25) constraint constraint_name not null,column_name3 number(7)) tablespace tablespace_name;

/*給建立bitmap index分配的記憶體空間引數，以加速建索引*/
show parameter create_bit;

/*改變索引的儲存引數*/
alter index index_name pctfree 30 storage(initial 200k next 200k);

/*給索引手工分配一個分割槽*/
alter index index_name allocate extent (size 200k datafile '$ORACLE/oradata/..');

/*釋放索引中沒用的空間*/
alter index index_name deallocate unused;

/*索引重建*/
alter index index_name rebuild tablespace tablespace_name;

/*普通索引和反轉索引的互換*/
alter index index_name rebuild tablespace tablespace_name reverse;

/*重建索引時，不鎖表*/
alter index index_name rebuild online;

/*給索引整理碎片*/
alter index index_name COALESCE;

/*分析索引,事實上是更新統計的過程*/
analyze index index_name validate structure;

desc index_state;

drop index index_name;

alter index index_name monitoring usage;-----監視索引是否被用到

alter index index_name nomonitoring usage;----取消監視

/*有關索引資訊的檢視*/
select * from dba_indexes/dba_ind_columns/dbs_ind_expressions/v$object_usage;

########## 資料完整性的管理(Maintaining data integrity) ##########

alter table table_name drop constraint constraint_name;----drop 約束

alter table table_name add constraint constraint_name primary key(column_name1,column_name2);-----建立主鍵

alter table table_name add constraint constraint_name unique(column_name1,column_name2);---建立唯一約束

/*建立外來鍵約束*/
alter table table_name add constraint constraint_name foreign key(column_name1) references table_name(column_name1);

/*不效驗老資料，只約束新的資料[enable/disable：約束/不約束新資料;novalidate/validate:不對/對老資料進行驗證]*/
alter table table_name add constraint constraint_name check(column_name like 'B%') enable/disable novalidate/validate;

/*修改約束條件，延時驗證，commit時驗證*/
alter table table_name modify constraint constraint_name initially deferred;

/*修改約束條件，立即驗證*/
alter table table_name modify constraint constraint_name initially immediate;

alter session set constraints=deferred/immediate;

/*drop一個有外來鍵的主鍵表,帶cascade constraints引數級聯刪除*/
drop table table_name cascade constraints;

/*當truncate外來鍵表時，先將外來鍵設為無效，再truncate;*/
truncate table table_name;

/*設約束條件無效*/
alter table table_name disable constraint constraint_name;

alter table table_name enable novalidate constraint constraint_name;

/*將無效約束的資料行放入exception的表中，此表記錄了違反資料約束的行的行號；在此之前，要先建exceptions表*/
alter table table_name add constraint constraint_name check(column_name >;15) enable validate exceptions into exceptions;

/*執行建立exceptions表的指令碼*/
start $ORACLE_HOME/rdbms/admin/utlexcpt.sql;

/*獲取約束條件資訊的表或檢視*/
select * from user_constraints/dba_constraints/dba_cons_columns;

################## managing password security and resources ####################

alter user user_name account unlock/open;----鎖定/開啟使用者;

alter user user_name password expire;---設定口令到期

/*建立口令配置檔案,failed_login_attempts口令輸多少次後鎖，password_lock_times指多少天后口令被自動解鎖*/
create profile profile_name limit failed_login_attempts 3 password_lock_times 1/1440;
/*建立口令配置檔案*/
create profile profile_name limit failed_login_attempts 3 password_lock_time unlimited password_life_time 30 password_reuse_time 30 password_verify_function verify_function password_grace_time 5;
/*建立資源配置檔案*/
create profile prfile_name limit session_per_user 2 cpu_per_session 10000 idle_time 60 connect_time 480;

alter user user_name profile profile_name;

/*設定口令解鎖時間*/
alter profile profile_name limit password_lock_time 1/24;

/*password_life_time指口令檔案多少時間到期，password_grace_time指在第一次成功登入後到口令到期有多少天時間可改變口令*/
alter profile profile_name limit password_lift_time 2 password_grace_time 3;

/*password_reuse_time指口令在多少天內可被重用,password_reuse_max口令可被重用的最大次數*/
alter profile profile_name limit password_reuse_time 10[password_reuse_max 3];

alter user user_name identified by input_password;-----修改使用者口令

drop profile profile_name;

/*建立了profile後，且指定給某個使用者，則必須用CASCADE才能刪除*/
drop profile profile_name CASCADE;

alter system set resource_limit=true;---啟用自願限制,預設是false

/*配置資源引數*/
alter profile profile_name limit cpu_per_session 10000 connect_time 60 idle_time 5;
/*資源引數(session級)
  cpu_per_session  每個session佔用cpu的時間 單位1/100秒
  sessions_per_user 允許每個使用者的並行session數
  connect_time 允許連線的時間 單位分鐘
  idle_time 連線被空閒多少時間後，被自動斷開 單位分鐘
  logical_reads_per_session 讀塊數
  private_sga 使用者能夠在SGA中使用的私有的空間數 單位bytes

  (call級)
  cpu_per_call 每次(1/100秒)呼叫cpu的時間
  logical_reads_per_call 每次呼叫能夠讀的塊數
*/

alter profile profile_name limit cpu_per_call 1000 logical_reads_per_call 10;

desc dbms_resouce_manager;---資源管理器包

/*獲取資源資訊的表或檢視*/
select * from dba_users/dba_profiles;

###### Managing users ############

show parameter os;

create user testuser1 identified by kxf_001;

grant connect,createtable to testuser1;

alter user testuser1 quota 10m on tablespace_name;

/*建立使用者*/
create user user_name identified by password default tablespace tablespace_name temporary tablespace tablespace_name quota 15m on tablespace_name password expire;

/*資料庫級設定預設臨時表空間*/
alter database default temporary tablespace tablespace_name;

/*制定資料庫級的預設表空間*/
alter database default tablespace tablespace_name;

/*建立os級稽核的使用者，需知道os_authent_prefix，表示oracle和os口令對應的字首,'OPS$'為此引數的值，此值可以任意設定*/
create user user_name identified by externally default OPS$tablespace_name tablespace_name temporary tablespace tablespace_name quota 15m on tablespace_name password expire;

/*修改使用者使用表空間的限額,回滾表空間和臨時表空間不允許授予限額*/
alter user user_name quota 5m on tablespace_name;

/*刪除使用者或刪除級聯使用者(使用者物件下有物件的要用CASCADE，將其下一些物件一起刪除)*/
drop user user_name [CASCADE];

/*每個使用者在哪些表空間下有些什麼限額*/
desc dba_ts_quotas;select * from dba_ts_quotas where username='...';

/*改變使用者的預設表空間*/
alter user user_name default tablespace tablespace_name;

######### Managing Privileges #############

grant create table,create session to user_name;

grant create any table to user_name;  revoke create any table from user_name;

/*授予許可權語法,public 標識所有使用者,with admin option允許能將許可權授予第三者的許可權*/
grant system_privs,[......] to [user/role/public],[....] [with admin option];

select * from v$pwfile_users;

/*當 O7_dictionary_accessiblity引數為True時，標識select any table時，包括系統表也能select ,否則，不包含系統表;預設為false*/
show parameter O7;

/*由於 O7_dictionary_accessiblity為靜態引數，不能動態改變，故加scope=spfile,下次啟動時才生效*/
alter system set O7_dictionary_accessiblity=true scope=spfile;

/*授予物件中的某些欄位的許可權，如select 某表中的某些欄位的許可權*/
grant [object_privs(column,....)],[...] on object_name to user/role/public,... with grant option;

/*oracle不允許授予select某列的許可權,但可以授insert ,update某列的許可權*/
grant insert(column_name1,column_name2,...) on table_name to user_name with grant option;

select * from dba_sys_privs/session_privs/dba_tab_privs/user_tab_privs/dba_col_privs/user_col_privs;

/*db/os/none  審計被記錄在 資料庫/作業系統/不審計 預設是none*/
show parameter audit_trail;

/*啟動對錶的select動作*/
audit select on user.table_name by session;

/*by session在每個session中發出command只記錄一次，by access則每個command都記錄*/
audit [create table][select/update/insert on object by session/access][whenever successful/not successful];

desc dbms_fga;---進一步設計，則可使用dbms_fgs包

/*取消審計*/
noaudit select on user.table_name;

/*查被審計資訊*/
select * from all_def_audit_opts/dba_stmt_audit_opts/dba_priv_audit_opts/dba_obj_audit_opts;

/*獲取審計記錄*/
select * from dba_audit_trail/dba_audit_exists/dba_audit_object/dba_audit_session/dba_audit_statement;

########### Managing Role #################

create role role_name;  grant select on table_name to role_name;  grant role_name to user_name; set role role_name;

create role role_name;
create role role_name identified by password;
create role role_name identified externally;

set role role_name ; ----啟用role
set role role_name identified by password;

alter role role_name not identified;
alter role role_name identified by password;
alter role role_name identified externally;

grant priv_name to role_name [WITH ADMIN OPTION];
grant update(column_name1,col_name2,...) on table_name to role_name;
grant role_name1 to role_name2;

/*建立default role,使用者登入時，預設啟用default role*/
alter user user_name default role role_name1,role_name2,...;
alter user user_name default role all;
alter user user_name default role all except role_name1,...;
alter user user_name default role none;

set role role1 [identified by password],role2,....;
set role all;
set role except role1,role2,...;
set role none;

revoke role_name from user_name;
revoke role_name from public;

drop role role_name;

select * from dba_roles/dba_role_privs/role_role_privs/dba_sys_privs/role_sys_privs/role_tab_privs/session_roles;

########### Basic SQL SELECT ################

select col_name as col_alias from table_name ;

select col_name from table_name where col1 like '_o%'; ----'_'匹配單個字元

/*使用字元函式(右邊擷取,欄位中包含某個字元,左邊填充某字元到固定位數,右邊填充某字元到固定位數)*/
select substr(col1,-3,5),instr(col2,'g'),LPAD(col3,10,'$'),RPAD(col4,10,'%') from table_name;

/*使用數字函式(往右/左幾位四捨五入,取整,取餘)*/
select round(col1,-2),trunc(col2),mod(col3) from table_name ;

/*使用日期函式(計算兩個日期間相差幾個星期,兩個日期間相隔幾個月,在某個月份上加幾個月,某個日期的下一個日期,
  某日期所在月的最後的日期,對某個日期的月分四捨五入，對某個日期的月份進行取整)*/
select (sysdate-col1)/7 week,months_between(sysdate,col1),add_months(col1,2),next_day(sysdate,'FRIDAY'),last_day(sysdate),
round(sysdate,'MONTH'),trunc(sysdate,'MONTH') from table_name;

/*使用NULL函式(當expr1為空取expr2/當expr1為空取expr2,否則取expr3/當expr1=expr2返回空)*/
select nvl(expr1,expr2),nvl2(expr1,expr2,expr3),nullif(expr1,expr2) from table_name;

select column1,column2,column3, case column2 when '50' then column2*1.1
                                             when '30' then column2*2.1
                                             when '10' then column3/20
                                else column3
                                end as ttt
                                from table_name ;           ------使用case函式

select table1.col1,table2.col2 from table1
[CROSS JOIN table2] |                 -----笛卡兒連線
[NATURAL JOIN table2] |               -----用兩個表中的同名列連線   
[JOIN table2 USING (column_name)] |   -----用兩個表中的同名列中的某一列或幾列連線
[JOIN table2
   ON (table1.col1=table2.col2)] |
[LEFT|RIGHT|FULL OUTER JOIN table2      ------相當於(+)=,=(+)連線,全外連線
   ON (table1.col1=table2.col2)]; ------SQL 1999中的JOIN語法;

example:
select col1,col2 from table1 t1
join table2 t2
on t1.col1=t2.col2 and t1.col3=t2.col1
join table3 t3
on t2.col1=t3.col3;

select * from table_name where col1 < any (select col2 from table_name2 where continue group by col3);

select * from table_name where col1 < all (select col2 from table_name2 where continue group by col3);

insert into (select col1,col2,col3 form. table_name where col1>; 50 with check option) values (value1,value2,value3);

MERGE INTO table_name table1
USING table_name2 table2
ON (table1.col1=table2.col2)
WHEN MATCHED THEN
UPDATE SET
  table1.col1=table2.col2,
  table1.col2=table2.col3,
  ...
WHEN NOT MATCHED THEN
INSERT VALUES(table2.col1,table2.col2,table2.col3,...); -----合併語句

##################### CREATE/ALTER TABLE #######################

alter table table_name drop column column_name ;---drop column

alter table table_name set unused (col1,col2,...);----設定列無效，這個比較快。
alter table table_name drop unused columns;---刪除被設為無效的列

rename table_name1 to table_name2; ---重新命名錶

comment on table table_name is 'comment message';----給表放入註釋資訊

create table table_name
(col1 int not null,col2 varchar2(20),col3 varchar2(20),
constraint uk_test2_1 unique(col2,col3)));               -----定義表中的約束條件

alter table table_name add constraint pk_test2 primary key(col1,col2,...);  ----建立主鍵

/*建立外來鍵*/
create table table_name (rid int,name varchar2(20),constraint fk_test3 foreign key(rid) references other_table_name(id));

alter table table_name add constraint ck_test3 check(name like 'K%');

alter table table_name drop constraint constraint_name;

alter table table_name drop primary key cascade;----級聯刪除主鍵

alter table table_name disable/enable constraint constraint_name;----使約束暫時無效

/*刪除列，並級聯刪除此列下的約束條件*/
alter table table_name drop column column_name cascade constraint;

select * from user_constraints/user_cons_columns;---約束條件相關檢視

############## Create Views #####################

CREATE [OR REPLACE] [FORCE|NOFORCE] VIEW view_name [(alias[,alias]...)]
AS subquery
[WITH CHECK OPTION [CONSTRAINT constraint_name]]
[WITH READ ONLY [CONSTRAINT constraint_name]];            ------建立檢視的語法

example:  Create or replace view testview as select col1,col2,col3 from table_name; ------建立檢視
          /*使用別名*/
          Create or replace view testview as select col1,sum(col2) col2_alias from table_name;
          /*建立複雜檢視*/
          Create view view_name (alias1,alias2,alias3,alias4) as select d.col1,min(e.col1),max(e.col1),avg(e.col1) from table_name1 e,table_name2 d where e.col2=d.col2 group by d.col1;
          /*當用update修改資料時，必須滿足檢視的col1>;10的條件，不滿足則不能被改變.*/
          Create or replace view view_name as select * from table_name where col1>;10 with check option;

/*改變檢視的值.對於簡單檢視可以用update語法修改表資料，但複雜檢視則不一定能改。如使用了函式，group by ,distinct等的列*/
update view_name set col1=value1;

/*TOP-N分析*/
select [column_list],rownum from (select [column_list] from table_name order by Top-N_column) where rownum<=N;

/*找出某列三條最大值的記錄*/
example: select rownum as rank ,col1 ,col2 from (select col1 ,col2 from table_name order by col2 desc) where rownum<=3;

############# Other database Object ###############

CREATE SEQUENCE sequence_name [INCREMENT BY n]
                              [START WITH n]
                              [{MAXVALUE n | NOMAXVALUE}]
                              [{MINVALUE n | NOMINVALUE}]
                              [{CYCEL | NOCYCLE}]
                              [{CACHE n | NOCACHE}];      -----建立SEQUENCE

example:
CREATE SEQUENCE sequence_name INCREMENT BY 10
                              START WITH 120
                              MAXVALUE 9999
                              NOCACHE
                              NOCYCLE;

select * from user_sequences ;---當前使用者下記錄sequence的檢視

select sequence_name.nextval,sequence_name.currval from dual;-----sequence的引用

alter sequence sequence_name INCREMENT BY 20
                             MAXVALUE 999999
                             NOCACHE
                             NOCYCLE;  -----修改sequence,不能改變起始序號

drop sequence sequence_name; ----刪除sequence

CREATE [PUBLIC] SYNONYM synonym_name FOR object; ------建立同義詞

DROP [PUBLIC] SYNONYM synonym_name;----刪除同義詞

CREATE PUBLIC DATABASE LINK link_name USEING OBJECT;----建立DBLINK

select * from object_name@link_name; ----訪問遠端資料庫中的物件

/*union 操作，它將兩個集合的交集部分壓縮，並對資料排序*/
select col1,col2,col3 from table1_name union select col1,col2,col3 from table2_name;

/*union all 操作，兩個集合的交集部分不壓縮，且不對資料排序*/
select col1,col2,col3 from table1_name union all select col1,col2,col3 from table2_name;

/*intersect 操作，求兩個集合的交集,它將對重複資料進行壓縮，且排序*/
select col1,col2,col3 from table1_name intersect select col1,col2,col3 from table2_name;

/*minus 操作，集合減,它將壓縮兩個集合減後的重複記錄, 且對資料排序*/
select col1,col2,col3 from table1_name minus select col1,col2,col3 from table2_name;

/*EXTRACT 抽取時間函式. 此例是抽取當前日期中的年*/
select EXTRACT(YEAR FROM SYSDATE) from dual;
/*EXTRACT 抽取時間函式. 此例是抽取當前日期中的月*/
select EXTRACT(MONTH FROM SYSDATE) from dual;

########################## 增強的 group by 子句 #########################

select [column,] group_function(column)...
from table
[WHERE condition]
[GROUP BY [ROLLUP] group_by_expression]
[HAVING having_expression];
[ORDER BY column];     -------ROLLUP操作字，對group by子句的各欄位從右到左進行再聚合

example:
/*其結果看起來象對col1做小計*/
select col1,col2,sum(col3) from table group by rollup(col1,col2);
/*複合rollup表示式*/
select col1,col2,sum(col3) from table group by rollup((col1,col2));

select [column,] group_function(column)...
from table
[WHERE condition]
[GROUP BY [CUBE] group_by_expression]
[HAVING having_expression];
[ORDER BY column];     -------CUBE操作字，除完成ROLLUP的功能外，再對ROLLUP後的結果集從右到左再聚合

example:
/*其結果看起來象對col1做小計後，再對col2做小計，最後算總計*/
select col1,col2,sum(col3) from table group by cube(col1,col2);
/*複合rollup表示式*/
select col1,col2,sum(col3) from table group by cube((col1,col2));
/*混合rollup,cube表示式*/
select col1,col2,col3,sum(col4) from table group by col1,rollup(col2),cube(col3);

/*GROUPING(expr)函式，檢視select語句種以何欄位聚合，其取值為0或1*/
select [column,] group_function(column)...,GROUPING(expr)
from table
[WHERE condition]
[GROUP BY [ROLLUP] group_by_expression]
[HAVING having_expression];
[ORDER BY column];

example:
select col1,col2,sum(col3),grouping(col1),grouping(col2) from table group by cube(col1,col2);

/*grouping sets操作，對group by結果集先對col1求和，再對col2求和，最後將其結果集並在一起*/
select col1,col2,sum(col3) from table group by grouping sets((col1),(col2));