【Oracle】常用语句集合

   1 oracle常用经典SQL查询 
   2 常用SQL查询：
   3  
   4 1、查看表空间的名称及大小
   5  
   6 select t.tablespace_name, round(sum(bytes/(1024*1024)),0) ts_size
   7 from dba_tablespaces t, dba_data_files d
   8 where t.tablespace_name = d.tablespace_name
   9 group by t.tablespace_name;
  10  
  11 2、查看表空间物理文件的名称及大小
  12  
  13 select tablespace_name, file_id, file_name,
  14 round(bytes/(1024*1024),0) total_space
  15 from dba_data_files
  16 order by tablespace_name;
  17  
  18 3、查看回滚段名称及大小
  19  
  20 select segment_name, tablespace_name, r.status, 
  21 (initial_extent/1024) InitialExtent,(next_extent/1024) NextExtent, 
  22 max_extents, v.curext CurExtent
  23 From dba_rollback_segs r, v$rollstat v
  24 Where r.segment_id = v.usn(+)
  25 order by segment_name;
  26  
  27 4、查看控制文件
  28  
  29 select name from v$controlfile;
  30  
  31 5、查看日志文件
  32  
  33 select member from v$logfile;
  34  
  35 6、查看表空间的使用情况
  36  
  37 select sum(bytes)/(1024*1024) as free_space,tablespace_name 
  38 from dba_free_space
  39 group by tablespace_name;
  40  
  41 SELECT A.TABLESPACE_NAME,A.BYTES TOTAL,B.BYTES USED, C.BYTES FREE,
  42 (B.BYTES*100)/A.BYTES "% USED",(C.BYTES*100)/A.BYTES "% FREE"
  43 FROM SYS.SM$TS_AVAIL A,SYS.SM$TS_USED B,SYS.SM$TS_FREE C
  44 WHERE A.TABLESPACE_NAME=B.TABLESPACE_NAME AND A.TABLESPACE_NAME=C.TABLESPACE_NAME; 
  45  
  46 7、查看数据库库对象
  47  
  48 select owner, object_type, status, count(*) count# from all_objects group by owner, object_type, status;
  49  
  50 8、查看数据库的版本　
  51  
  52 Select version FROM Product_component_version 
  53 Where SUBSTR(PRODUCT,1,6)=‘Oracle‘;
  54  
  55 9、查看数据库的创建日期和归档方式
  56  
  57 Select Created, Log_Mode, Log_Mode From V$Database; 
  58  
  59 10、捕捉运行很久的SQL
  60  
  61 column username format a12 
  62 column opname format a16 
  63 column progress format a8 
  64  
  65 select username,sid,opname, 
  66       round(sofar*100 / totalwork,0) || ‘%‘ as progress, 
  67       time_remaining,sql_text 
  68 from v$session_longops , v$sql 
  69 where time_remaining <> 0 
  70 and sql_address = address 
  71 and sql_hash_value = hash_value 
  72 /
  73 11。查看数据表的参数信息
  74 SELECT   partition_name, high_value, high_value_length, tablespace_name,
  75         pct_free, pct_used, ini_trans, max_trans, initial_extent,
  76         next_extent, min_extent, max_extent, pct_increase, FREELISTS,
  77         freelist_groups, LOGGING, BUFFER_POOL, num_rows, blocks,
  78         empty_blocks, avg_space, chain_cnt, avg_row_len, sample_size,
  79         last_analyzed
  80    FROM dba_tab_partitions
  81   --WHERE table_name = :tname AND table_owner = :towner
  82 ORDER BY partition_position
  83  
  84 12.查看还没提交的事务
  85 select * from v$locked_object;
  86 select * from v$transaction;
  87  
  88 13。查找object为哪些进程所用
  89 select 
  90 p.spid,
  91 s.sid,
  92 s.serial# serial_num,
  93 s.username user_name,
  94 a.type  object_type,
  95 s.osuser os_user_name,
  96 a.owner,
  97 a.object object_name,
  98 decode(sign(48 - command),
  99 1,
 100 to_char(command), ‘Action Code #‘ || to_char(command) ) action,
 101 p.program oracle_process,
 102 s.terminal terminal,
 103 s.program program,
 104 s.status session_status   
 105 from v$session s, v$access a, v$process p   
 106 where s.paddr = p.addr and
 107      s.type = ‘USER‘ and    
 108      a.sid = s.sid   and
 109   a.object=‘SUBSCRIBER_ATTR‘
 110 order by s.username, s.osuser
 111  
 112 14。回滚段查看
 113 select rownum, sys.dba_rollback_segs.segment_name Name, v$rollstat.extents 
 114 Extents, v$rollstat.rssize Size_in_Bytes, v$rollstat.xacts XActs, 
 115 v$rollstat.gets Gets, v$rollstat.waits Waits, v$rollstat.writes Writes, 
 116 sys.dba_rollback_segs.status status from v$rollstat, sys.dba_rollback_segs, 
 117 v$rollname where v$rollname.name(+) = sys.dba_rollback_segs.segment_name and 
 118 v$rollstat.usn (+) = v$rollname.usn order by rownum
 119  
 120 15。耗资源的进程（top session）
 121 select s.schemaname schema_name,    decode(sign(48 - command), 1, 
 122 to_char(command), ‘Action Code #‘ || to_char(command) ) action,    status 
 123 session_status,   s.osuser os_user_name,   s.sid,         p.spid ,         s.serial# serial_num,   
 124 nvl(s.username, ‘[Oracle process]‘) user_name,   s.terminal terminal,    
 125 s.program program,   st.value criteria_value  from v$sesstat st,   v$session s  , v$process p   
 126 where st.sid = s.sid and   st.statistic# = to_number(‘38‘) and   (‘ALL‘ = ‘ALL‘ 
 127 or s.status = ‘ALL‘) and p.addr = s.paddr order by st.value desc,  p.spid asc, s.username asc, s.osuser asc
 128  
 129 16。查看锁（lock）情况
 130 select /*+ RULE */ ls.osuser os_user_name,   ls.username user_name,   
 131 decode(ls.type, ‘RW‘, ‘Row wait enqueue lock‘, ‘TM‘, ‘DML enqueue lock‘, ‘TX‘, 
 132 ‘Transaction enqueue lock‘, ‘UL‘, ‘User supplied lock‘) lock_type,   
 133 o.object_name object,   decode(ls.lmode, 1, null, 2, ‘Row Share‘, 3, 
 134 ‘Row Exclusive‘, 4, ‘Share‘, 5, ‘Share Row Exclusive‘, 6, ‘Exclusive‘, null) 
 135 lock_mode,    o.owner,   ls.sid,   ls.serial# serial_num,   ls.id1,   ls.id2    
 136 from sys.dba_objects o, (   select s.osuser,    s.username,    l.type,     
 137 l.lmode,    s.sid,    s.serial#,    l.id1,    l.id2   from v$session s,     
 138 v$lock l   where s.sid = l.sid ) ls  where o.object_id = ls.id1 and    o.owner 
 139 <> ‘SYS‘   order by o.owner, o.object_name
 140  
 141 17。查看等待（wait）情况
 142 SELECT v$waitstat.class, v$waitstat.count count, SUM(v$sysstat.value) sum_value 
 143 FROM v$waitstat, v$sysstat WHERE v$sysstat.name IN (‘db block gets‘, 
 144 ‘consistent gets‘) group by v$waitstat.class, v$waitstat.count
 145  
 146 18。查看sga情况
 147 SELECT NAME, BYTES FROM SYS.V_$SGASTAT ORDER BY NAME ASC
 148  
 149 19。查看catched object
 150 SELECT owner,              name,              db_link,              namespace,  
 151            type,              sharable_mem,              loads,              executions,   
 152           locks,              pins,              kept        FROM v$db_object_cache
 153           
 154 20。查看V$SQLAREA
 155 SELECT SQL_TEXT, SHARABLE_MEM, PERSISTENT_MEM, RUNTIME_MEM, SORTS, 
 156 VERSION_COUNT, LOADED_VERSIONS, OPEN_VERSIONS, USERS_OPENING, EXECUTIONS, 
 157 USERS_EXECUTING, LOADS, FIRST_LOAD_TIME, INVALIDATIONS, PARSE_CALLS, DISK_READS,
 158 BUFFER_GETS, ROWS_PROCESSED FROM V$SQLAREA
 159  
 160 21。查看object分类数量
 161 select decode (o.type#,1,‘INDEX‘ , 2,‘TABLE‘ , 3 , ‘CLUSTER‘ , 4, ‘VIEW‘ , 5 , 
 162 ‘SYNONYM‘ , 6 , ‘SEQUENCE‘ , ‘OTHER‘ ) object_type , count(*) quantity from 
 163 sys.obj$ o where o.type# > 1 group by decode (o.type#,1,‘INDEX‘ , 2,‘TABLE‘ , 3 
 164 , ‘CLUSTER‘ , 4, ‘VIEW‘ , 5 , ‘SYNONYM‘ , 6 , ‘SEQUENCE‘ , ‘OTHER‘ ) union select 
 165 ‘COLUMN‘ , count(*) from sys.col$ union select ‘DB LINK‘ , count(*) from 
 166  
 167 22。按用户查看object种类
 168 select u.name schema,   sum(decode(o.type#, 1, 1, NULL)) indexes,   
 169 sum(decode(o.type#, 2, 1, NULL)) tables,   sum(decode(o.type#, 3, 1, NULL)) 
 170 clusters,   sum(decode(o.type#, 4, 1, NULL)) views,   sum(decode(o.type#, 5, 1, 
 171 NULL)) synonyms,   sum(decode(o.type#, 6, 1, NULL)) sequences,   
 172 sum(decode(o.type#, 1, NULL, 2, NULL, 3, NULL, 4, NULL, 5, NULL, 6, NULL, 1)) 
 173 others   from sys.obj$ o, sys.user$ u   where o.type# >= 1 and    u.user# = 
 174 o.owner# and   u.name <> ‘PUBLIC‘   group by u.name    order by 
 175 sys.link$ union select ‘CONSTRAINT‘ , count(*) from sys.con$
 176  
 177 23。有关connection的相关信息
 178 1）查看有哪些用户连接
 179 select s.osuser os_user_name,    decode(sign(48 - command), 1, to_char(command),
 180 ‘Action Code #‘ || to_char(command) ) action,     p.program oracle_process,     
 181 status session_status,    s.terminal terminal,    s.program program,    
 182 s.username user_name,    s.fixed_table_sequence activity_meter,    ‘‘ query,    
 183 0 memory,    0 max_memory,     0 cpu_usage,    s.sid,   s.serial# serial_num    
 184 from v$session s,    v$process p   where s.paddr=p.addr and    s.type = ‘USER‘  
 185 order by s.username, s.osuser
 186 2）根据v.sid查看对应连接的资源占用等情况
 187 select n.name, 
 188  v.value, 
 189  n.class,
 190  n.statistic#  
 191 from  v$statname n, 
 192  v$sesstat v 
 193 where v.sid = 71 and 
 194  v.statistic# = n.statistic# 
 195 order by n.class, n.statistic#
 196 3）根据sid查看对应连接正在运行的sql
 197 select /*+ PUSH_SUBQ */
 198  command_type, 
 199  sql_text, 
 200  sharable_mem, 
 201  persistent_mem, 
 202  runtime_mem, 
 203  sorts, 
 204  version_count, 
 205  loaded_versions, 
 206  open_versions, 
 207  users_opening, 
 208  executions, 
 209  users_executing, 
 210  loads, 
 211  first_load_time, 
 212  invalidations, 
 213  parse_calls, 
 214  disk_reads, 
 215  buffer_gets, 
 216  rows_processed,
 217  sysdate start_time,
 218  sysdate finish_time,
 219  ‘>‘ || address sql_address,
 220  ‘N‘ status 
 221 from v$sqlarea
 222 where address = (select sql_address from v$session where sid = 71)
 223  
 224 24．查询表空间使用情况
 225 select a.tablespace_name "表空间名称",
 226 100-round((nvl(b.bytes_free,0)/a.bytes_alloc)*100,2) "占用率(%)",
 227 round(a.bytes_alloc/1024/1024,2) "容量(M)",
 228 round(nvl(b.bytes_free,0)/1024/1024,2) "空闲(M)",
 229 round((a.bytes_alloc-nvl(b.bytes_free,0))/1024/1024,2) "使用(M)",
 230 Largest "最大扩展段(M)",
 231 to_char(sysdate,‘yyyy-mm-dd hh24:mi:ss‘) "采样时间" 
 232 from  (select f.tablespace_name,
 233    sum(f.bytes) bytes_alloc,
 234    sum(decode(f.autoextensible,‘YES‘,f.maxbytes,‘NO‘,f.bytes)) maxbytes 
 235 from dba_data_files f 
 236 group by tablespace_name) a,
 237 (select  f.tablespace_name,
 238     sum(f.bytes) bytes_free 
 239 from dba_free_space f 
 240 group by tablespace_name) b,
 241 (select round(max(ff.length)*16/1024,2) Largest,
 242    ts.name tablespace_name 
 243 from sys.fet$ ff, sys.file$ tf,sys.ts$ ts 
 244 where ts.ts#=ff.ts# and ff.file#=tf.relfile# and ts.ts#=tf.ts# 
 245 group by ts.name, tf.blocks) c 
 246 where a.tablespace_name = b.tablespace_name and a.tablespace_name = c.tablespace_name
 247  
 248 25. 查询表空间的碎片程度 
 249  
 250 select tablespace_name,count(tablespace_name) from dba_free_space group by tablespace_name 
 251 having count(tablespace_name)>10; 
 252  
 253 alter tablespace name coalesce; 
 254 alter table name deallocate unused; 
 255  
 256 create or replace view ts_blocks_v as 
 257 select tablespace_name,block_id,bytes,blocks,‘free space‘ segment_name from dba_free_space 
 258 union all 
 259 select tablespace_name,block_id,bytes,blocks,segment_name from dba_extents; 
 260  
 261 select * from ts_blocks_v; 
 262  
 263 select tablespace_name,sum(bytes),max(bytes),count(block_id) from dba_free_space 
 264 group by tablespace_name;
 265  
 266 26。查询有哪些数据库实例在运行
 267 select inst_name from v$active_instances;
 268  
 269 ===========================================================
 270 ######### 创建数据库----look $ORACLE_HOME/rdbms/admin/buildall.sql ############# 
 271  
 272 create database db01 
 273 maxlogfiles 10 
 274 maxdatafiles 1024 
 275 maxinstances 2 
 276 logfile 
 277 GROUP 1 (‘/u01/oradata/db01/log_01_db01.rdo‘) SIZE 15M, 
 278 GROUP 2 (‘/u01/oradata/db01/log_02_db01.rdo‘) SIZE 15M, 
 279 GROUP 3 (‘/u01/oradata/db01/log_03_db01.rdo‘) SIZE 15M, 
 280 datafile ‘u01/oradata/db01/system_01_db01.dbf‘) SIZE 100M, 
 281 undo tablespace UNDO 
 282 datafile ‘/u01/oradata/db01/undo_01_db01.dbf‘ SIZE 40M 
 283 default temporary tablespace TEMP 
 284 tempfile ‘/u01/oradata/db01/temp_01_db01.dbf‘ SIZE 20M 
 285 extent management local uniform size 128k 
 286 character set AL32UTE8 
 287 national character set AL16UTF16 
 288 set time_zone=‘America/New_York‘; 
 289  
 290 ############### 数据字典 ########## 
 291  
 292 set wrap off 
 293  
 294 select * from v$dba_users; 
 295  
 296 grant select on table_name to user/rule; 
 297  
 298 select * from user_tables; 
 299  
 300 select * from all_tables; 
 301  
 302 select * from dba_tables; 
 303  
 304 revoke dba from user_name; 
 305  
 306 shutdown immediate 
 307  
 308 startup nomount 
 309  
 310 select * from v$instance; 
 311  
 312 select * from v$sga; 
 313  
 314 select * from v$tablespace; 
 315  
 316 alter session set nls_language=american; 
 317  
 318 alter database mount; 
 319  
 320 select * from v$database; 
 321  
 322 alter database open; 
 323  
 324 desc dictionary 
 325  
 326 select * from dict; 
 327  
 328 desc v$fixed_table; 
 329  
 330 select * from v$fixed_table; 
 331  
 332 set oracle_sid=foxconn 
 333  
 334 select * from dba_objects; 
 335  
 336 set serveroutput on 
 337  
 338 execute dbms_output.put_line(‘sfasd‘); 
 339  
 340 ############# 控制文件 ########### 
 341  
 342 select * from v$database; 
 343  
 344 select * from v$tablespace; 
 345  
 346 select * from v$logfile; 
 347  
 348 select * from v$log; 
 349  
 350 select * from v$backup; 
 351  
 352 /*备份用户表空间*/ 
 353 alter tablespace users begin backup; 
 354  
 355 select * from v$archived_log; 
 356  
 357 select * from v$controlfile; 
 358  
 359 alter system set control_files=‘$ORACLE_HOME/oradata/u01/ctrl01.ctl‘, 
 360 ‘$ORACLE_HOME/oradata/u01/ctrl02.ctl‘ scope=spfile; 
 361  
 362 cp $ORACLE_HOME/oradata/u01/ctrl01.ctl $ORACLE_HOME/oradata/u01/ctrl02.ctl 
 363  
 364 startup pfile=‘../initSID.ora‘ 
 365  
 366 select * from v$parameter where name like ‘control%‘ ; 
 367  
 368 show parameter control; 
 369  
 370 select * from v$controlfile_record_section; 
 371  
 372 select * from v$tempfile; 
 373  
 374 /*备份控制文件*/ 
 375 alter database backup controlfile to ‘../filepath/control.bak‘; 
 376  
 377 /*备份控制文件，并将二进制控制文件变为了asc 的文本文件*/ 
 378 alter database backup controlfile to trace; 
 379  
 380 ############### redo log ############## 
 381  
 382 archive log list; 
 383  
 384 alter system archive log start;--启动自动存档 
 385  
 386 alter system switch logfile;--强行进行一次日志switch 
 387  
 388 alter system checkpoint;--强制进行一次checkpoint 
 389  
 390 alter tablspace users begin backup; 
 391  
 392 alter tablespace offline; 
 393  
 394 /*checkpoint 同步频率参数FAST_START_MTTR_TARGET,同步频率越高，系统恢复所需时间越短*/ 
 395 show parameter fast; 
 396  
 397 show parameter log_checkpoint; 
 398  
 399 /*加入一个日志组*/ 
 400 alter database add logfile group 3 (‘/$ORACLE_HOME/oracle/ora_log_file6.rdo‘ size 10M); 
 401  
 402 /*加入日志组的一个成员*/ 
 403 alter database add logfile member ‘/$ORACLE_HOME/oracle/ora_log_file6.rdo‘ to group 3; 
 404  
 405 /*删除日志组:当前日志组不能删；活动的日志组不能删；非归档的日志组不能删*/ 
 406 alter database drop logfile group 3; 
 407  
 408 /*删除日志组中的某个成员，但每个组的最后一个成员不能被删除*/ 
 409 alter databse drop logfile member ‘$ORACLE_HOME/oracle/ora_log_file6.rdo‘; 
 410  
 411 /*清除在线日志*/ 
 412 alter database clear logfile ‘$ORACLE_HOME/oracle/ora_log_file6.rdo‘; 
 413  
 414 alter database clear logfile group 3; 
 415  
 416 /*清除非归档日志*/ 
 417 alter database clear unarchived logfile group 3; 
 418  
 419 /*重命名日志文件*/ 
 420 alter database rename file ‘$ORACLE_HOME/oracle/ora_log_file6.rdo‘ to ‘$ORACLE_HOME/oracle/ora_log_file6a.rdo‘; 
 421  
 422 show parameter db_create; 
 423  
 424 alter system set db_create_online_log_dest_1=‘path_name‘; 
 425  
 426 select * from v$log; 
 427  
 428 select * from v$logfile; 
 429  
 430 /*数据库归档模式到非归档模式的互换,要启动到mount状态下才能改变;startup mount;然后再打开数据库.*/ 
 431 alter database noarchivelog/archivelog; 
 432  
 433 achive log start;---启动自动归档 
 434  
 435 alter system archive all;－－手工归档所有日志文件 
 436  
 437 select * from v$archived_log; 
 438  
 439 show parameter log_archive; 
 440  
 441 ###### 分析日志文件logmnr ############## 
 442  
 443 1) 在init.ora中set utl_file_dir 参数 
 444 2) 重新启动oracle 
 445 3) create 目录文件 
 446 desc dbms_logmnr_d; 
 447 dbms_logmnr_d.build; 
 448 4) 加入日志文件 add/remove log file 
 449 dhms_logmnr.add_logfile 
 450 dbms_logmnr.removefile 
 451 5) start logmnr 
 452 dbms_logmnr.start_logmnr 
 453 6) 分析出来的内容查询 v$logmnr_content --sqlredo/sqlundo 
 454  
 455 实践： 
 456  
 457 desc dbms_logmnr_d; 
 458  
 459 /*对数据表做一些操作，为恢复操作做准备*/ 
 460 update 表 set qty=10 where stor_id=6380; 
 461  
 462 delete 表 where stor_id=7066; 
 463 /***********************************/ 
 464 utl_file_dir的路径 
 465 execute dbms_logmnr_d.build(‘foxdict.ora‘,‘$ORACLE_HOME/oracle/admin/fox/cdump‘); 
 466  
 467 execute dbms_logmnr.add_logfile(‘$ORACLE_HOME/oracle/ora_log_file6.log‘,dbms_logmnr.newfile); 
 468  
 469 execute dbms_logmnr.start_logmnr(dictfilename=>‘$ORACLE_HOME/oracle/admin/fox/cdump/foxdict.ora‘); 
 470  
 471 ######### tablespace ############## 
 472  
 473 select * form v$tablespace; 
 474  
 475 select * from v$datafile; 
 476  
 477 /*表空间和数据文件的对应关系*/ 
 478 select t1.name,t2.name from v$tablespace t1,v$datafile t2 where t1.ts#=t2.ts#; 
 479  
 480 alter tablespace users add datafile ‘path‘ size 10M; 
 481  
 482 select * from dba_rollback_segs; 
 483  
 484 /*限制用户在某表空间的使用限额*/ 
 485 alter user user_name quota 10m on tablespace_name; 
 486  
 487 create tablespace xxx [datafile ‘path_name/datafile_name‘] [size xxx] [extent management local/dictionary] [default storage(xxx)]; 
 488  
 489 exmple: create tablespace userdata datafile ‘$ORACLE_HOME/oradata/userdata01.dbf‘ size 100M AUTOEXTEND ON NEXT 5M MAXSIZE 200M; 
 490 create tablespace userdata datafile ‘$ORACLE_HOME/oradata/userdata01.dbf‘ size 100M extent management dictionary default storage(initial 100k next 100k pctincrease 10) offline; 
 491 /*9i以后，oracle建议使用local管理，而不使用dictionary管理，因为local采用bitmap管理表空间 ，不会产生系统表空间的自愿争用;*/ 
 492 create tablespace userdata datafile ‘$ORACLE_HOME/oradata/userdata01.dbf‘ size 100M extent management local uniform size 1m; 
 493 create tablespace userdata datafile ‘$ORACLE_HOME/oradata/userdata01.dbf‘ size 100M extent management local autoallocate; 
 494 /*在创建表空间时，设置表空间内的段空间管理模式，这里用的是自动管理*/ 
 495 create tablespace userdata datafile ‘$ORACLE_HOME/oradata/userdata01.dbf‘ size 100M extent management local uniform size 1m segment space management auto; 
 496  
 497 alter tablespace userdata mininum extent 10; 
 498  
 499 alter tablespace userdata default storage(initial 1m next 1m pctincrease 20); 
 500  
 501 /*undo tablespace(不能被用在字典管理模下) */ 
 502 create undo tablespace undo1 datafile ‘$ORACLE_HOME/oradata/undo101.dbf‘ size 40M extent management local; 
 503  
 504 show parameter undo; 
 505  
 506 /*temporary tablespace*/ 
 507 create temporary tablespace userdata tempfile ‘$ORACLE_HOME/oradata/undo101.dbf‘ size 10m extent management local; 
 508  
 509 /*设置数据库缺省的临时表空间*/ 
 510 alter database default temporary tablespace tablespace_name; 
 511  
 512 /*系统/临时/在线的undo表空间不能被offline*/ 
 513 alter tablespace tablespace_name offline/online; 
 514  
 515 alter tablespace tablespace_name read only; 
 516  
 517 /*重命名用户表空间*/ 
 518 alter tablespace tablespace_name rename datafile ‘$ORACLE_HOME/oradata/undo101.dbf‘ to ‘$ORACLE_HOME/oradata/undo102.dbf‘; 
 519  
 520 /*重命名系统表空间 ,但在重命名前必须将数据库shutdown,并重启到mount状态*/ 
 521 alter database rename file ‘$ORACLE_HOME/oradata/system01.dbf‘ to ‘$ORACLE_HOME/oradata/system02.dbf‘; 
 522  
 523 drop tablespace userdata including contents and datafiles;---drop tablespce 
 524  
 525 /*resize tablespace,autoextend datafile space*/ 
 526 alter database datafile ‘$ORACLE_HOME/oradata/undo102.dbf‘ autoextend on next 10m maxsize 500M; 
 527  
 528 /*resize datafile*/ 
 529 alter database datafile ‘$ORACLE_HOME/oradata/undo102.dbf‘ resize 50m; 
 530  
 531 /*给表空间扩展空间*/ 
 532 alter tablespace userdata add datafile ‘$ORACLE_HOME/oradata/undo102.dbf‘ size 10m; 
 533  
 534 /*将表空间设置成OMF状态*/ 
 535 alter system set db_create_file_dest=‘$ORACLE_HOME/oradata‘; 
 536  
 537 create tablespace userdata;---use OMF status to create tablespace; 
 538  
 539 drop tablespace userdata;---user OMF status to drop tablespace; 
 540  
 541 select * from dba_tablespace/v$tablespace/dba_data_files; 
 542  
 543 /*将表的某分区移动到另一个表空间*/ 
 544 alter table table_name move partition partition_name tablespace tablespace_name; 
 545  
 546 ###### ORACLE storage structure and relationships ######### 
 547  
 548 /*手工分配表空间段的分区(extend)大小*/ 
 549 alter table kong.test12 allocate extent(size 1m datafile ‘$ORACLE_HOME/oradata/undo102.dbf‘); 
 550  
 551 alter table kong.test12 deallocate unused; ---释放表中没有用到的分区 
 552  
 553 show parameter db; 
 554  
 555 alter system set db_8k_cache_size=10m; ---配置8k块的内存空间块参数 
 556  
 557 select * from dba_extents/dba_segments/data_tablespace; 
 558  
 559 select * from dba_free_space/dba_data_file/data_tablespace; 
 560  
 561 /*数据对象所占用的字节数*/ 
 562 select sum(bytes) from dba_extents where onwer=‘kong‘ and segment_name =‘table_name‘; 
 563  
 564 ############ UNDO Data ################ 
 565  
 566 show parameter undo; 
 567  
 568 alter tablespace users offline normal; 
 569  
 570 alter tablespace users offline immediate; 
 571  
 572 recover datafile ‘$ORACLE_HOME/oradata/undo102.dbf‘; 
 573  
 574 alter tablespace users online ; 
 575  
 576 select * from dba_rollback_segs; 
 577  
 578 alter system set undo_tablespace=undotbs1; 
 579  
 580 /*忽略回滚段的错误提示*/ 
 581 alter system set undo_suppress_errors=true; 
 582  
 583 /*在自动管理模式下,不会真正建立rbs1;在手工管理模式则可以建立,且是私有回滚段*/ 
 584 create rollback segment rbs1 tablespace undotbs; 
 585  
 586 desc dbms_flashback; 
 587  
 588 /*在提交了修改的数据后,9i提供了旧数据的回闪操作,将修改前的数据只读给用户看,但这部分数据不会又恢复在表中,而是旧数据的一个映射*/ 
 589 execute dbms_flashback.enable_at_time(‘26-JAN-04:12:17:00 pm‘); 
 590  
 591 execute dbms_flashback.disable; 
 592  
 593 /*回滚段的统计信息*/ 
 594 select end_time,begin_time,undoblks from v$undostat; 
 595  
 596 /*undo表空间的大小计算公式: UndoSpace=[UR * (UPS * DBS)] + (DBS * 24) 
 597 UR :UNDO_RETENTION 保留的时间(秒) 
 598 UPS :每秒的回滚数据块 
 599 DBS:系统EXTENT和FILE SIZE(也就是db_block_size)*/ 
 600  
 601 select * from dba_rollback_segs/v$rollname/v$rollstat/v$undostat/v$session/v$transaction; 
 602  
 603 show parameter transactions; 
 604  
 605 show parameter rollback; 
 606  
 607 /*在手工管理模式下,建立公共的回滚段*/ 
 608 create public rollback segment prbs1 tablespace undotbs; 
 609  
 610 alter rollback segment rbs1 online;----在手工管理模式 
 611  
 612 /*在手工管理模式中,initSID.ora中指定 undo_management=manual 、rollback_segment=(‘rbs1‘,‘rbs2‘,...)、 
 613 transactions=100 、transactions_per_rollback_segment=10 
 614 然后 shutdown immediate ,startup pfile=....\???.ora */ 
 615  
 616 ########## Managing Tables ########### 
 617  
 618 /*char type maxlen=2000;varchar2 type maxlen=4000 bytes 
 619 rowid 是18位的64进制字符串 (10个bytes 80 bits) 
 620 rowid组成: object#(对象号)--32bits,6位 
 621 rfile#(相对文件号)--10bits,3位 
 622 block#(块号)--22bits,6位 
 623 row#(行号)--16bits,3位 
 624 64进制: A-Z,a-z,0-9,/,+ 共64个符号 
 625  
 626 dbms_rowid 包中的函数可以提供对rowid的解释*/ 
 627  
 628 select rowid,dbms_rowid.rowid_block_number(rowid),dbms_rowid.rowid_row_number(rowid) from table_name; 
 629  
 630 create table test2 
 631 ( 
 632 id int, 
 633 lname varchar2(20) not null, 
 634 fname varchar2(20) constraint ck_1 check(fname like ‘k%‘), 
 635 empdate date default sysdate) 
 636 ) tablespace tablespace_name; 
 637  
 638  
 639 create global temporary table test2 on commit delete/preserve rows as select * from kong.authors; 
 640  
 641 create table user.table(...) tablespace tablespace_name storage(...) pctfree10 pctused 40; 
 642  
 643 alter table user.tablename pctfree 20 pctused 50 storage(...);---changing table storage 
 644  
 645 /*手工分配分区,分配的数据文件必须是表所在表空间内的数据文件*/ 
 646 alter table user.table_name allocate extent(size 500k datafile ‘...‘); 
 647  
 648 /*释放表中没有用到的空间*/ 
 649 alter table table_name deallocate unused; 
 650  
 651 alter table table_name deallocate unused keep 8k; 
 652  
 653 /*将非分区表的表空间搬到新的表空间,在移动表空间后，原表中的索引对象将会不可用，必须重建*/ 
 654 alter table user.table_name move tablespace new_tablespace_name; 
 655  
 656 create index index_name on user.table_name(column_name) tablespace users; 
 657  
 658 alter index index_name rebuild; 
 659  
 660 drop table table_name [CASCADE CONSTRAINTS]; 
 661  
 662 alter table user.table_name drop column col_name [CASCADE CONSTRAINTS CHECKPOINT 1000];---drop column 
 663  
 664 /*给表中不用的列做标记*/ 
 665 alter table user.table_name set unused column comments CASCADE CONSTRAINTS; 
 666  
 667 /*drop表中不用的做了标记列*/ 
 668 alter table user.table_name drop unused columns checkpoint 1000; 
 669  
 670 /*当在drop col是出现异常，使用CONTINUE，防止重删前面的column*/ 
 671 ALTER TABLE USER.TABLE_NAME DROP COLUMNS CONTINUE CHECKPOINT 1000; 
 672  
 673 select * from dba_tables/dba_objects; 
 674  
 675 ######## managing indexes ########## 
 676  
 677 /*create index*/ 
 678 example: 
 679 /*创建一般索引*/ 
 680 create index index_name on table_name(column_name) tablespace tablespace_name; 
 681 /*创建位图索引*/ 
 682 create bitmap index index_name on table_name(column_name1,column_name2) tablespace tablespace_name; 
 683 /*索引中不能用pctused*/ 
 684 create [bitmap] index index_name on table_name(column_name) tablespace tablespace_name pctfree 20 storage(inital 100k next 100k) ; 
 685 /*大数据量的索引最好不要做日志*/ 
 686 create [bitmap] index index_name table_name(column_name1,column_name2) tablespace_name pctfree 20 storage(inital 100k next 100k) nologging; 
 687 /*创建反转索引*/ 
 688 create index index_name on table_name(column_name) reverse; 
 689 /*创建函数索引*/ 
 690 create index index_name on table_name(function_name(column_name)) tablespace tablespace_name; 
 691 /*建表时创建约束条件*/ 
 692 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; 
 693  
 694 /*给创建bitmap index分配的内存空间参数，以加速建索引*/ 
 695 show parameter create_bit; 
 696  
 697 /*改变索引的存储参数*/ 
 698 alter index index_name pctfree 30 storage(initial 200k next 200k); 
 699  
 700 /*给索引手工分配一个分区*/ 
 701 alter index index_name allocate extent (size 200k datafile ‘$ORACLE/oradata/..‘); 
 702  
 703 /*释放索引中没用的空间*/ 
 704 alter index index_name deallocate unused; 
 705  
 706 /*索引重建*/ 
 707 alter index index_name rebuild tablespace tablespace_name; 
 708  
 709 /*普通索引和反转索引的互换*/ 
 710 alter index index_name rebuild tablespace tablespace_name reverse; 
 711  
 712 /*重建索引时，不锁表*/ 
 713 alter index index_name rebuild online; 
 714  
 715 /*给索引整理碎片*/ 
 716 alter index index_name COALESCE; 
 717  
 718 /*分析索引,事实上是更新统计的过程*/ 
 719 analyze index index_name validate structure; 
 720  
 721 desc index_state; 
 722  
 723 drop index index_name; 
 724  
 725 alter index index_name monitoring usage;-----监视索引是否被用到 
 726  
 727 alter index index_name nomonitoring usage;----取消监视 
 728  
 729 /*有关索引信息的视图*/ 
 730 select * from dba_indexes/dba_ind_columns/dbs_ind_expressions/v$object_usage; 
 731  
 732 ########## 数据完整性的管理(Maintaining data integrity) ########## 
 733  
 734 alter table table_name drop constraint constraint_name;----drop 约束 
 735  
 736 alter table table_name add constraint constraint_name primary key(column_name1,column_name2);-----创建主键 
 737  
 738 alter table table_name add constraint constraint_name unique(column_name1,column_name2);---创建唯一约束 
 739  
 740 /*创建外键约束*/ 
 741 alter table table_name add constraint constraint_name foreign key(column_name1) references table_name(column_name1); 
 742  
 743 /*不效验老数据，只约束新的数据[enable/disable：约束/不约束新数据;novalidate/validate:不对/对老数据进行验证]*/ 
 744 alter table table_name add constraint constraint_name check(column_name like ‘B%‘) enable/disable novalidate/validate; 
 745  
 746 /*修改约束条件，延时验证，commit时验证*/ 
 747 alter table table_name modify constraint constraint_name initially deferred; 
 748  
 749 /*修改约束条件，立即验证*/ 
 750 alter table table_name modify constraint constraint_name initially immediate; 
 751  
 752 alter session set constraints=deferred/immediate; 
 753  
 754 /*drop一个有外键的主键表,带cascade constraints参数级联删除*/ 
 755 drop table table_name cascade constraints; 
 756  
 757 /*当truncate外键表时，先将外键设为无效，再truncate;*/ 
 758 truncate table table_name; 
 759  
 760 /*设约束条件无效*/ 
 761 alter table table_name disable constraint constraint_name; 
 762  
 763 alter table table_name enable novalidate constraint constraint_name; 
 764  
 765 /*将无效约束的数据行放入exception的表中，此表记录了违反数据约束的行的行号；在此之前，要先建exceptions表*/ 
 766 alter table table_name add constraint constraint_name check(column_name >15) enable validate exceptions into exceptions; 
 767  
 768 /*运行创建exceptions表的脚本*/ 
 769 start $ORACLE_HOME/rdbms/admin/utlexcpt.sql; 
 770  
 771 /*获取约束条件信息的表或视图*/ 
 772 select * from user_constraints/dba_constraints/dba_cons_columns; 
 773  
 774 ################## managing password security and resources #################### 
 775  
 776 alter user user_name account unlock/open;----锁定/打开用户; 
 777  
 778 alter user user_name password expire;---设定口令到期 
 779  
 780 /*建立口令配置文件,failed_login_attempts口令输多少次后锁，password_lock_times指多少天后口令被自动解锁*/ 
 781 create profile profile_name limit failed_login_attempts 3 password_lock_times 1/1440; 
 782 /*创建口令配置文件*/ 
 783 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; 
 784 /*建立资源配置文件*/ 
 785 create profile prfile_name limit session_per_user 2 cpu_per_session 10000 idle_time 60 connect_time 480; 
 786  
 787 alter user user_name profile profile_name; 
 788  
 789 /*设置口令解锁时间*/ 
 790 alter profile profile_name limit password_lock_time 1/24; 
 791  
 792 /*password_life_time指口令文件多少时间到期，password_grace_time指在第一次成功登录后到口令到期有多少天时间可改变口令*/ 
 793 alter profile profile_name limit password_lift_time 2 password_grace_time 3; 
 794  
 795 /*password_reuse_time指口令在多少天内可被重用,password_reuse_max口令可被重用的最大次数*/ 
 796 alter profile profile_name limit password_reuse_time 10[password_reuse_max 3]; 
 797  
 798 alter user user_name identified by input_password;-----修改用户口令 
 799  
 800 drop profile profile_name; 
 801  
 802 /*建立了profile后，且指定给某个用户，则必须用CASCADE才能删除*/ 
 803 drop profile profile_name CASCADE; 
 804  
 805 alter system set resource_limit=true;---启用自愿限制,缺省是false 
 806  
 807 /*配置资源参数*/ 
 808 alter profile profile_name limit cpu_per_session 10000 connect_time 60 idle_time 5; 
 809 /*资源参数(session级) 
 810 cpu_per_session 每个session占用cpu的时间 单位1/100秒 
 811 sessions_per_user 允许每个用户的并行session数 
 812 connect_time 允许连接的时间 单位分钟 
 813 idle_time 连接被空闲多少时间后，被自动断开 单位分钟 
 814 logical_reads_per_session 读块数 
 815 private_sga 用户能够在SGA中使用的私有的空间数 单位bytes 
 816  
 817 (call级) 
 818 cpu_per_call 每次(1/100秒)调用cpu的时间 
 819 logical_reads_per_call 每次调用能够读的块数 
 820 */ 
 821  
 822 alter profile profile_name limit cpu_per_call 1000 logical_reads_per_call 10; 
 823  
 824 desc dbms_resouce_manager;---资源管理器包 
 825  
 826 /*获取资源信息的表或视图*/ 
 827 select * from dba_users/dba_profiles; 
 828  
 829 ###### Managing users ############ 
 830  
 831 show parameter os; 
 832  
 833 create user testuser1 identified by kxf_001; 
 834  
 835 grant connect,createtable to testuser1; 
 836  
 837 alter user testuser1 quota 10m on tablespace_name; 
 838  
 839 /*创建用户*/ 
 840 create user user_name identified by password default tablespace tablespace_name temporary tablespace tablespace_name quota 15m on tablespace_name password expire; 
 841  
 842 /*数据库级设定缺省临时表空间*/ 
 843 alter database default temporary tablespace tablespace_name; 
 844  
 845 /*制定数据库级的缺省表空间*/ 
 846 alter database default tablespace tablespace_name; 
 847  
 848 /*创建os级审核的用户，需知道os_authent_prefix，表示oracle和os口令对应的前缀,‘OPS$‘为此参数的值，此值可以任意设置*/ 
 849 create user user_name identified by externally default OPS$tablespace_name tablespace_name temporary tablespace tablespace_name quota 15m on tablespace_name password expire; 
 850  
 851 /*修改用户使用表空间的限额,回滚表空间和临时表空间不允许授予限额*/ 
 852 alter user user_name quota 5m on tablespace_name; 
 853  
 854 /*删除用户或删除级联用户(用户对象下有对象的要用CASCADE，将其下一些对象一起删除)*/ 
 855 drop user user_name [CASCADE]; 
 856  
 857 /*每个用户在哪些表空间下有些什么限额*/ 
 858 desc dba_ts_quotas;select * from dba_ts_quotas where username=‘...‘; 
 859  
 860 /*改变用户的缺省表空间*/ 
 861 alter user user_name default tablespace tablespace_name; 
 862  
 863 ######### Managing Privileges ############# 
 864  
 865 grant create table,create session to user_name; 
 866  
 867 grant create any table to user_name; revoke create any table from user_name; 
 868  
 869 /*授予权限语法,public 标识所有用户,with admin option允许能将权限授予第三者的权限*/ 
 870 grant system_privs,[......] to [user/role/public],[....] [with admin option]; 
 871  
 872 select * from v$pwfile_users; 
 873  
 874 /*当 O7_dictionary_accessiblity参数为True时，标识select any table时，包括系统表也能select ,否则，不包含系统表;缺省为false*/ 
 875 show parameter O7; 
 876  
 877 /*由于 O7_dictionary_accessiblity为静态参数，不能动态改变，故加scope=spfile,下次启动时才生效*/ 
 878 alter system set O7_dictionary_accessiblity=true scope=spfile; 
 879  
 880 /*授予对象中的某些字段的权限，如select 某表中的某些字段的权限*/ 
 881 grant [object_privs(column,....)],[...] on object_name to user/role/public,... with grant option; 
 882  
 883 /*oracle不允许授予select某列的权限,但可以授insert ,update某列的权限*/ 
 884 grant insert(column_name1,column_name2,...) on table_name to user_name with grant option; 
 885  
 886 select * from dba_sys_privs/session_privs/dba_tab_privs/user_tab_privs/dba_col_privs/user_col_privs; 
 887  
 888 /*db/os/none 审计被记录在 数据库/操作系统/不审计 缺省是none*/ 
 889 show parameter audit_trail; 
 890  
 891 /*启动对表的select动作*/ 
 892 audit select on user.table_name by session; 
 893  
 894 /*by session在每个session中发出command只记录一次，by access则每个command都记录*/ 
 895 audit [create table][select/update/insert on object by session/access][whenever successful/not successful]; 
 896  
 897 desc dbms_fga;---进一步设计，则可使用dbms_fgs包 
 898  
 899 /*取消审计*/ 
 900 noaudit select on user.table_name; 
 901  
 902 /*查被审计信息*/ 
 903 select * from all_def_audit_opts/dba_stmt_audit_opts/dba_priv_audit_opts/dba_obj_audit_opts; 
 904  
 905 /*获取审计记录*/ 
 906 select * from dba_audit_trail/dba_audit_exists/dba_audit_object/dba_audit_session/dba_audit_statement; 
 907  
 908 ########### Managing Role ################# 
 909  
 910 create role role_name; grant select on table_name to role_name; grant role_name to user_name; set role role_name; 
 911  
 912 create role role_name; 
 913 create role role_name identified by password; 
 914 create role role_name identified externally; 
 915  
 916 set role role_name ; ----激活role 
 917 set role role_name identified by password; 
 918  
 919 alter role role_name not identified; 
 920 alter role role_name identified by password; 
 921 alter role role_name identified externally; 
 922  
 923 grant priv_name to role_name [WITH ADMIN OPTION]; 
 924 grant update(column_name1,col_name2,...) on table_name to role_name; 
 925 grant role_name1 to role_name2; 
 926  
 927 /*建立default role,用户登录时，缺省激活default role*/ 
 928 alter user user_name default role role_name1,role_name2,...; 
 929 alter user user_name default role all; 
 930 alter user user_name default role all except role_name1,...; 
 931 alter user user_name default role none; 
 932  
 933 set role role1 [identified by password],role2,....; 
 934 set role all; 
 935 set role except role1,role2,...; 
 936 set role none; 
 937  
 938 revoke role_name from user_name; 
 939 revoke role_name from public; 
 940  
 941 drop role role_name; 
 942  
 943 select * from dba_roles/dba_role_privs/role_role_privs/dba_sys_privs/role_sys_privs/role_tab_privs/session_roles; 
 944  
 945 ########### Basic SQL SELECT ################ 
 946  
 947 select col_name as col_alias from table_name ; 
 948  
 949 select col_name from table_name where col1 like ‘_o%‘; ----‘_‘匹配单个字符 
 950  
 951 /*使用字符函数(右边截取,字段中包含某个字符,左边填充某字符到固定位数,右边填充某字符到固定位数)*/ 
 952 select substr(col1,-3,5),instr(col2,‘g‘),LPAD(col3,10,‘$‘),RPAD(col4,10,‘%‘) from table_name; 
 953  
 954 /*使用数字函数(往右/左几位四舍五入,取整,取余)*/ 
 955 select round(col1,-2),trunc(col2),mod(col3) from table_name ; 
 956  
 957 /*使用日期函数(计算两个日期间相差几个星期,两个日期间相隔几个月,在某个月份上加几个月,某个日期的下一个日期, 
 958 某日期所在月的最后的日期,对某个日期的月分四舍五入，对某个日期的月份进行取整)*/ 
 959 select (sysdate-col1)/7 week,months_between(sysdate,col1),add_months(col1,2),next_day(sysdate,‘FRIDAY‘),last_day(sysdate), 
 960 round(sysdate,‘MONTH‘),trunc(sysdate,‘MONTH‘) from table_name; 
 961  
 962 /*使用NULL函数(当expr1为空取expr2/当expr1为空取expr2,否则取expr3/当expr1=expr2返回空)*/ 
 963 select nvl(expr1,expr2),nvl2(expr1,expr2,expr3),nullif(expr1,expr2) from table_name; 
 964  
 965 select column1,column2,column3, case column2 when ‘50‘ then column2*1.1 
 966 when ‘30‘ then column2*2.1 
 967 when ‘10‘ then column3/20 
 968 else column3 
 969 end as ttt 
 970 from table_name ; ------使用case函数 
 971  
 972 select table1.col1,table2.col2 from table1 
 973 [CROSS JOIN table2] | -----笛卡儿连接 
 974 [NATURAL JOIN table2] | -----用两个表中的同名列连接 
 975 [JOIN table2 USING (column_name)] | -----用两个表中的同名列中的某一列或几列连接 
 976 [JOIN table2 
 977 ON (table1.col1=table2.col2)] | 
 978 [LEFT|RIGHT|FULL OUTER JOIN table2 ------相当于(+)=,=(+)连接,全外连接 
 979 ON (table1.col1=table2.col2)]; ------SQL 1999中的JOIN语法; 
 980  
 981 example: 
 982 select col1,col2 from table1 t1 
 983 join table2 t2 
 984 on t1.col1=t2.col2 and t1.col3=t2.col1 
 985 join table3 t3 
 986 on t2.col1=t3.col3; 
 987  
 988 select * from table_name where col1 < any (select col2 from table_name2 where continue group by col3); 
 989  
 990 select * from table_name where col1 < all (select col2 from table_name2 where continue group by col3); 
 991  
 992 insert into (select col1,col2,col3 form table_name where col1> 50 with check option) values (value1,value2,value3); 
 993  
 994 MERGE INTO table_name table1 
 995 USING table_name2 table2 
 996 ON (table1.col1=table2.col2) 
 997 WHEN MATCHED THEN 
 998 UPDATE SET 
 999 table1.col1=table2.col2, 
1000 table1.col2=table2.col3, 
1001 ... 
1002 WHEN NOT MATCHED THEN 
1003 INSERT VALUES(table2.col1,table2.col2,table2.col3,...); -----合并语句 
1004  
1005 ##################### CREATE/ALTER TABLE ####################### 
1006  
1007 alter table table_name drop column column_name ;---drop column 
1008  
1009 alter table table_name set unused (col1,col2,...);----设置列无效，这个比较快。 
1010 alter table table_name drop unused columns;---删除被设为无效的列 
1011  
1012 rename table_name1 to table_name2; ---重命名表 
1013  
1014 comment on table table_name is ‘comment message‘;----给表放入注释信息 
1015  
1016 create table table_name 
1017 (col1 int not null,col2 varchar2(20),col3 varchar2(20), 
1018 constraint uk_test2_1 unique(col2,col3))); -----定义表中的约束条件 
1019  
1020 alter table table_name add constraint pk_test2 primary key(col1,col2,...); ----创建主键 
1021  
1022 /*建立外键*/ 
1023 create table table_name (rid int,name varchar2(20),constraint fk_test3 foreign key(rid) references other_table_name(id)); 
1024  
1025 alter table table_name add constraint ck_test3 check(name like ‘K%‘); 
1026  
1027 alter table table_name drop constraint constraint_name; 
1028  
1029 alter table table_name drop primary key cascade;----级联删除主键 
1030  
1031 alter table table_name disable/enable constraint constraint_name;----使约束暂时无效 
1032  
1033 /*删除列，并级联删除此列下的约束条件*/ 
1034 alter table table_name drop column column_name cascade constraint; 
1035  
1036 select * from user_constraints/user_cons_columns;---约束条件相关视图 
1037  
1038 ############## Create Views ##################### 
1039  
1040 CREATE [OR REPLACE] [FORCE|NOFORCE] VIEW view_name [(alias[,alias]...)] 
1041 AS subquery 
1042 [WITH CHECK OPTION [CONSTRAINT constraint_name]] 
1043 [WITH READ ONLY [CONSTRAINT constraint_name]]; ------创建视图的语法 
1044  
1045 example: Create or replace view testview as select col1,col2,col3 from table_name; ------创建视图 
1046 /*使用别名*/ 
1047 Create or replace view testview as select col1,sum(col2) col2_alias from table_name; 
1048 /*创建复杂视图*/ 
1049 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; 
1050 /*当用update修改数据时，必须满足视图的col1>10的条件，不满足则不能被改变.*/ 
1051 Create or replace view view_name as select * from table_name where col1>10 with check option; 
1052  
1053 /*改变视图的值.对于简单视图可以用update语法修改表数据，但复杂视图则不一定能改。如使用了函数，group by ,distinct等的列*/ 
1054 update view_name set col1=value1; 
1055  
1056 /*TOP-N分析*/ 
1057 select [column_list],rownum from (select [column_list] from table_name order by Top-N_column) where rownum<=N; 
1058  
1059 /*找出某列三条最大值的记录*/ 
1060 example: select rownum as rank ,col1 ,col2 from (select col1 ,col2 from table_name order by col2 desc) where rownum<=3; 
1061  
1062 ############# Other database Object ############### 
1063  
1064 CREATE SEQUENCE sequence_name [INCREMENT BY n] 
1065 [START WITH n] 
1066 [{MAXVALUE n | NOMAXVALUE}] 
1067 [{MINVALUE n | NOMINVALUE}] 
1068 [{CYCEL | NOCYCLE}] 
1069 [{CACHE n | NOCACHE}]; -----创建SEQUENCE 
1070  
1071 example: 
1072 CREATE SEQUENCE sequence_name INCREMENT BY 10 
1073 START WITH 120 
1074 MAXVALUE 9999 
1075 NOCACHE 
1076 NOCYCLE; 
1077  
1078 select * from user_sequences ;---当前用户下记录sequence的视图 
1079  
1080 select sequence_name.nextval,sequence_name.currval from dual;-----sequence的引用 
1081  
1082 alter sequence sequence_name INCREMENT BY 20 
1083 MAXVALUE 999999 
1084 NOCACHE 
1085 NOCYCLE; -----修改sequence,不能改变起始序号 
1086  
1087 drop sequence sequence_name; ----删除sequence 
1088  
1089 CREATE [PUBLIC] SYNONYM synonym_name FOR object; ------创建同义词 
1090  
1091 DROP [PUBLIC] SYNONYM synonym_name;----删除同义词 
1092  
1093 CREATE PUBLIC DATABASE LINK link_name USEING OBJECT;----创建DBLINK 
1094  
1095 select * from object_name@link_name; ----访问远程数据库中的对象 
1096  
1097 /*union 操作，它将两个集合的交集部分压缩，并对数据排序*/ 
1098 select col1,col2,col3 from table1_name union select col1,col2,col3 from table2_name; 
1099  
1100 /*union all 操作，两个集合的交集部分不压缩，且不对数据排序*/ 
1101 select col1,col2,col3 from table1_name union all select col1,col2,col3 from table2_name; 
1102  
1103 /*intersect 操作，求两个集合的交集,它将对重复数据进行压缩，且排序*/ 
1104 select col1,col2,col3 from table1_name intersect select col1,col2,col3 from table2_name; 
1105  
1106 /*minus 操作，集合减,它将压缩两个集合减后的重复记录, 且对数据排序*/ 
1107 select col1,col2,col3 from table1_name minus select col1,col2,col3 from table2_name; 
1108  
1109 /*EXTRACT 抽取时间函数. 此例是抽取当前日期中的年*/ 
1110 select EXTRACT(YEAR FROM SYSDATE) from dual; 
1111 /*EXTRACT 抽取时间函数. 此例是抽取当前日期中的月*/ 
1112 select EXTRACT(MONTH FROM SYSDATE) from dual; 
1113  
1114 ########################## 增强的 group by 子句 ######################### 
1115  
1116 select [column,] group_function(column)... 
1117 from table 
1118 [WHERE condition] 
1119 [GROUP BY [ROLLUP] group_by_expression] 
1120 [HAVING having_expression]; 
1121 [ORDER BY column]; -------ROLLUP操作字，对group by子句的各字段从右到左进行再聚合 
1122  
1123 example: 
1124 /*其结果看起来象对col1做小计*/ 
1125 select col1,col2,sum(col3) from table group by rollup(col1,col2); 
1126 /*复合rollup表达式*/ 
1127 select col1,col2,sum(col3) from table group by rollup((col1,col2)); 
1128  
1129 select [column,] group_function(column)... 
1130 from table 
1131 [WHERE condition] 
1132 [GROUP BY [CUBE] group_by_expression] 
1133 [HAVING having_expression]; 
1134 [ORDER BY column]; -------CUBE操作字，除完成ROLLUP的功能外，再对ROLLUP后的结果集从右到左再聚合 
1135  
1136 example: 
1137 /*其结果看起来象对col1做小计后，再对col2做小计，最后算总计*/ 
1138 select col1,col2,sum(col3) from table group by cube(col1,col2); 
1139 /*复合rollup表达式*/ 
1140 select col1,col2,sum(col3) from table group by cube((col1,col2)); 
1141 /*混合rollup,cube表达式*/ 
1142 select col1,col2,col3,sum(col4) from table group by col1,rollup(col2),cube(col3); 
1143  
1144 /*GROUPING(expr)函数，查看select语句种以何字段聚合，其取值为0或1*/ 
1145 select [column,] group_function(column)...,GROUPING(expr) 
1146 from table 
1147 [WHERE condition] 
1148 [GROUP BY [ROLLUP] group_by_expression] 
1149 [HAVING having_expression]; 
1150 [ORDER BY column]; 
1151  
1152 example: 
1153 select col1,col2,sum(col3),grouping(col1),grouping(col2) from table group by cube(col1,col2); 
1154  
1155 /*grouping sets操作，对group by结果集先对col1求和，再对col2求和，最后将其结果集并在一起*/ 
1156 select col1,col2,sum(col3) from table group by grouping sets((col1),(col2));