oracle常用函数

 
  SQL中的单记录函数
  1.ASCII
  返回与指定的字符对应的十进制数;
  SQL> select ascii('A') A,ascii('a') a,ascii('0') zero,ascii(' ') space from dual;
   A A ZERO SPACE
  --------- --------- --------- ---------
   65 97 48 32
  2.CHR
  给出整数,返回对应的字符;
  SQL> select chr(54740) zhao,chr(65) chr65 from dual;
  ZH C
  -- -
  赵 A
  3.CONCAT
  连接两个字符串;
  SQL> select concat('010-','88888888')||'转23' 高乾竞电话 from dual;
  高乾竞电话
  ----------------
  010-88888888转23
  4.INITCAP
  返回字符串并将字符串的第一个字母变为大写;
  SQL> select initcap('smith') upp from dual;
  UPP
  -----
  Smith
  5.INSTR(C1,C2,I,J)
  在一个字符串中搜索指定的字符,返回发现指定的字符的位置;
  C1 被搜索的字符串
  C2 希望搜索的字符串
  I 搜索的开始位置,默认为1
  J 出现的位置,默认为1
  SQL> select instr('oracle traning','ra',1,2) instring from dual;
   INSTRING
  ---------
   9
  6.LENGTH
  返回字符串的长度;
  SQL> select name,length(name),addr,length(addr),sal,length(to_char(sal)) from gao.nchar_tst;
  NAME LENGTH(NAME) ADDR LENGTH(ADDR) SAL LENGTH(TO_CHAR(SAL))
  ------ ------------ ---------------- ------------ --------- --------------------
  高乾竞 3 北京市海锭区 6 9999.99 7
  
  7.LOWER
  返回字符串,并将所有的字符小写
  SQL> select lower('AaBbCcDd')AaBbCcDd from dual;
  AABBCCDD
  --------
  aabbccdd
  8.UPPER
  返回字符串,并将所有的字符大写
  SQL> select upper('AaBbCcDd') upper from dual;
  UPPER
  --------
  AABBCCDD
  
  9.RPAD和LPAD(粘贴字符)
  RPAD 在列的右边粘贴字符
  LPAD 在列的左边粘贴字符
  SQL> select lpad(rpad('gao',10,'*'),17,'*')from dual;
  LPAD(RPAD('GAO',1
  -----------------
  *******gao*******
  不够字符则用*来填满
  10.LTRIM和RTRIM
  LTRIM 删除左边出现的字符串
  RTRIM 删除右边出现的字符串
  SQL> select ltrim(rtrim(' gao qian jing ',' '),' ') from dual;
  LTRIM(RTRIM('
  -------------
  gao qian jing
  11.SUBSTR(string,start,count)
  取子字符串,从start开始,取count个
  SQL> select substr('13088888888',3,8) from dual;
  SUBSTR('
  --------
  08888888
  12.REPLACE('string','s1','s2')
  string 希望被替换的字符或变量
  s1 被替换的字符串
  s2 要替换的字符串
  SQL> select replace('he love you','he','i') from dual;
  REPLACE('H
  ----------
  i love you
  13.SOUNDEX
  返回一个与给定的字符串读音相同的字符串
  SQL> create table table1(xm varchar(8));
  SQL> insert into table1 values('weather');
  SQL> insert into table1 values('wether');
  SQL> insert into table1 values('gao');
  SQL> select xm from table1 where soundex(xm)=soundex('weather');
  XM
  --------
  weather
  wether
  14.TRIM('s' from 'string')
  LEADING 剪掉前面的字符
  TRAILING 剪掉后面的字符
  如果不指定,默认为空格符
  15.ABS
  返回指定值的绝对值
  SQL> select abs(100),abs(-100) from dual;
   ABS(100) ABS(-100)
  --------- ---------
   100 100
  16.ACOS
  给出反余弦的值
  SQL> select acos(-1) from dual;
   ACOS(-1)
  ---------
  3.1415927
  17.ASIN
  给出反正弦的值
  SQL> select asin(0.5) from dual;
  ASIN(0.5)
  ---------
  .52359878
  18.ATAN
  返回一个数字的反正切值
  SQL> select atan(1) from dual;
   ATAN(1)
  ---------
  .78539816
  19.CEIL
  返回大于或等于给出数字的最小整数
  SQL> select ceil(3.1415927) from dual;
  CEIL(3.1415927)
  ---------------
   4
  20.COS
  返回一个给定数字的余弦
  SQL> select cos(-3.1415927) from dual;
  COS(-3.1415927)
  ---------------
   -1
  21.COSH
  返回一个数字反余弦值
  SQL> select cosh(20) from dual;
   COSH(20)
  ---------
  242582598
  22.EXP
  返回一个数字e的n次方根
  SQL> select exp(2),exp(1) from dual;
   EXP(2) EXP(1)
  --------- ---------
  7.3890561 2.7182818
  23.FLOOR
  对给定的数字取整数
  SQL> select floor(2345.67) from dual;
  FLOOR(2345.67)
  --------------
   2345
  24.LN
  返回一个数字的对数值
  SQL> select ln(1),ln(2),ln(2.7182818) from dual;
   LN(1) LN(2) LN(2.7182818)
  --------- --------- -------------
   0 .69314718 .99999999
  25.LOG(n1,n2)
  返回一个以n1为底n2的对数
  SQL> select log(2,1),log(2,4) from dual;
   LOG(2,1) LOG(2,4)
  --------- ---------
   0 2
  26.MOD(n1,n2)
  返回一个n1除以n2的余数
  SQL> select mod(10,3),mod(3,3),mod(2,3) from dual;
  MOD(10,3) MOD(3,3) MOD(2,3)
  --------- --------- ---------
   1 0 2
  27.POWER
  返回n1的n2次方根
  SQL> select power(2,10),power(3,3) from dual;
  POWER(2,10) POWER(3,3)
  ----------- ----------
   1024 27
  28.ROUND和TRUNC
  按照指定的精度进行舍入
  SQL> select round(55.5),round(-55.4),trunc(55.5),trunc(-55.5) from dual;
  ROUND(55.5) ROUND(-55.4) TRUNC(55.5) TRUNC(-55.5)
  ----------- ------------ ----------- ------------
   56 -55 55 -55
  29.SIGN
  取数字n的符号,大于0返回1,小于0返回-1,等于0返回0
  SQL> select sign(123),sign(-100),sign(0) from dual;
  SIGN(123) SIGN(-100) SIGN(0)
  --------- ---------- ---------
   1 -1 0
  30.SIN
  返回一个数字的正弦值
  SQL> select sin(1.57079) from dual;
  SIN(1.57079)
  ------------
   1
  31.SIGH
  返回双曲正弦的值
  SQL> select sin(20),sinh(20) from dual;
   SIN(20) SINH(20)
  --------- ---------
  .91294525 242582598
  32.SQRT
  返回数字n的根
  SQL> select sqrt(64),sqrt(10) from dual;
   SQRT(64) SQRT(10)
  --------- ---------
   8 3.1622777
  33.TAN
  返回数字的正切值
  SQL> select tan(20),tan(10) from dual;
   TAN(20) TAN(10)
  --------- ---------
  2.2371609 .64836083
  34.TANH
  返回数字n的双曲正切值
  SQL> select tanh(20),tan(20) from dual;
   TANH(20) TAN(20)
  --------- ---------
   1 2.2371609
  
  35.TRUNC
  按照指定的精度截取一个数
  SQL> select trunc(124.1666,-2) trunc1,trunc(124.16666,2) from dual;
   TRUNC1 TRUNC(124.16666,2)
  --------- ------------------
   100 124.16
  
  36.ADD_MONTHS
  增加或减去月份
  SQL> select to_char(add_months(to_date('199912','yyyymm'),2),'yyyymm') from dual;
  TO_CHA
  ------
  200002
  SQL> select to_char(add_months(to_date('199912','yyyymm'),-2),'yyyymm') from dual;
  TO_CHA
  ------
  199910
  37.LAST_DAY
  返回日期的最后一天
  SQL> select to_char(sysdate,'yyyy.mm.dd'),to_char((sysdate)+1,'yyyy.mm.dd') from dual;
  TO_CHAR(SY TO_CHAR((S
  ---------- ----------
  2004.05.09 2004.05.10
  SQL> select last_day(sysdate) from dual;
  LAST_DAY(S
  ----------
  31-5月 -04
  38.MONTHS_BETWEEN(date2,date1)
  给出date2-date1的月份
  SQL> select months_between('19-12月-1999','19-3月-1999') mon_between from dual;
  MON_BETWEEN
  -----------
   9
  SQL>selectmonths_between(to_date('2000.05.20','yyyy.mm.dd'),to_date('2005.05.20','yyyy.mm.dd')) mon_betw from dual;
   MON_BETW
  ---------
   -60
  39.NEW_TIME(date,'this','that')
  给出在this时区=other时区的日期和时间
  SQL> select to_char(sysdate,'yyyy.mm.dd hh24:mi:ss') bj_time,to_char(new_time
   2 (sysdate,'PDT','GMT'),'yyyy.mm.dd hh24:mi:ss') los_angles from dual;
  BJ_TIME LOS_ANGLES
  ------------------- -------------------
  2004.05.09 11:05:32 2004.05.09 18:05:32
  40.NEXT_DAY(date,'day')
  给出日期date和星期x之后计算下一个星期的日期
  SQL> select next_day('18-5月-2001','星期五') next_day from dual;
  NEXT_DAY
  ----------
  25-5月 -01
  
  41.SYSDATE
  用来得到系统的当前日期
  SQL> select to_char(sysdate,'dd-mm-yyyy day') from dual;
  TO_CHAR(SYSDATE,'
  -----------------
  09-05-2004 星期日
  trunc(date,fmt)按照给出的要求将日期截断,如果fmt='mi'表示保留分,截断秒
  SQL> select to_char(trunc(sysdate,'hh'),'yyyy.mm.dd hh24:mi:ss') hh,
   2 to_char(trunc(sysdate,'mi'),'yyyy.mm.dd hh24:mi:ss') hhmm from dual;
  HH HHMM
  ------------------- -------------------
  2004.05.09 11:00:00 2004.05.09 11:17:00
  
  42.CHARTOROWID
  将字符数据类型转换为ROWID类型
  SQL> select rowid,rowidtochar(rowid),ename from scott.emp;
  ROWID ROWIDTOCHAR(ROWID) ENAME
  ------------------ ------------------ ----------
  AAAAfKAACAAAAEqAAA AAAAfKAACAAAAEqAAA SMITH
  AAAAfKAACAAAAEqAAB AAAAfKAACAAAAEqAAB ALLEN
  AAAAfKAACAAAAEqAAC AAAAfKAACAAAAEqAAC WARD
  AAAAfKAACAAAAEqAAD AAAAfKAACAAAAEqAAD JONES
  43.CONVERT(c,dset,sset)
  将源字符串 sset从一个语言字符集转换到另一个目的dset字符集
  SQL> select convert('strutz','we8hp','f7dec') "conversion" from dual;
  conver
  ------
  strutz
  44.HEXTORAW
  将一个十六进制构成的字符串转换为二进制
  45.RAWTOHEXT
  将一个二进制构成的字符串转换为十六进制
  
  46.ROWIDTOCHAR
  将ROWID数据类型转换为字符类型
  
  47.TO_CHAR(date,'format')
  SQL> select to_char(sysdate,'yyyy/mm/dd hh24:mi:ss') from dual;
  TO_CHAR(SYSDATE,'YY
  -------------------
  2004/05/09 21:14:41
  
  48.TO_DATE(string,'format')
  将字符串转化为ORACLE中的一个日期
  49.TO_MULTI_BYTE
  将字符串中的单字节字符转化为多字节字符
  SQL> select to_multi_byte('高') from dual;
  TO
  --
  高
  50.TO_NUMBER
  将给出的字符转换为数字
  SQL> select to_number('1999') year from dual;
   YEAR
  ---------
   1999
  51.BFILENAME(dir,file)
  指定一个外部二进制文件
  SQL>insert into file_tb1 values(bfilename('lob_dir1','image1.gif'));
  52.CONVERT('x','desc','source')
  将x字段或变量的源source转换为desc
  SQL> select sid,serial#,username,decode(command,
   2 0,'none',
   3 2,'insert',
   4 3,
   5 'select',
   6 6,'update',
   7 7,'delete',
   8 8,'drop',
   9 'other') cmd from v$session where type!='background';
   SID SERIAL# USERNAME CMD
  --------- --------- ------------------------------ ------
   1 1 none
   2 1 none
   3 1 none
   4 1 none
   5 1 none
   6 1 none
   7 1275 none
   8 1275 none
   9 20 GAO select
   10 40 GAO none
  53.DUMP(s,fmt,start,length)
  DUMP函数以fmt指定的内部数字格式返回一个VARCHAR2类型的值
  SQL> col global_name for a30
  SQL> col dump_string for a50
  SQL> set lin 200
  SQL> select global_name,dump(global_name,1017,8,5) dump_string from global_name;
  GLOBAL_NAME DUMP_STRING
  ------------------------------ --------------------------------------------------
  ORACLE.WORLD Typ=1 Len=12 CharacterSet=ZHS16GBK: W,O,R,L,D
  54.EMPTY_BLOB()和EMPTY_CLOB()
  这两个函数都是用来对大数据类型字段进行初始化操作的函数
  55.GREATEST
  返回一组表达式中的最大值,即比较字符的编码大小.
  SQL> select greatest('AA','AB','AC') from dual;
  GR
  --
  AC
  SQL> select greatest('啊','安','天') from dual;
  GR
  --
  天
  56.LEAST
  返回一组表达式中的最小值
  SQL> select least('啊','安','天') from dual;
  LE
  --
  啊
  57.UID
  返回标识当前用户的唯一整数
  SQL> show user
  USER 为"GAO"
  SQL> select username,user_id from dba_users where user_id=uid;
  USERNAME USER_ID
  ------------------------------ ---------
  GAO 25
  
  58.USER
  返回当前用户的名字
  SQL> select user from dual;
  USER
  ------------------------------
  GAO
  59.USEREVN
  返回当前用户环境的信息,opt可以是:
  ENTRYID,SESSIONID,TERMINAL,ISDBA,LABLE,LANGUAGE,CLIENT_INFO,LANG,VSIZE
  ISDBA 查看当前用户是否是DBA如果是则返回true
  SQL> select userenv('isdba') from dual;
  USEREN
  ------
  FALSE
  SQL> select userenv('isdba') from dual;
  USEREN
  ------
  TRUE
  SESSION
  返回会话标志
  SQL> select userenv('sessionid') from dual;
  USERENV('SESSIONID')
  --------------------
   152
  ENTRYID
  返回会话人口标志
  SQL> select userenv('entryid') from dual;
  USERENV('ENTRYID')
  ------------------
   0
  INSTANCE
  返回当前INSTANCE的标志
  SQL> select userenv('instance') from dual;
  USERENV('INSTANCE')
  -------------------
   1
  LANGUAGE
  返回当前环境变量
  SQL> select userenv('language') from dual;
  USERENV('LANGUAGE')
  ----------------------------------------------------
  SIMPLIFIED CHINESE_CHINA.ZHS16GBK
  LANG
  返回当前环境的语言的缩写
  SQL> select userenv('lang') from dual;
  USERENV('LANG')
  ----------------------------------------------------
  ZHS
  TERMINAL
  返回用户的终端或机器的标志
  SQL> select userenv('terminal') from dual;
  USERENV('TERMINA
  ----------------
  GAO
  VSIZE(X)
  返回X的大小(字节)数
  SQL> select vsize(user),user from dual;
  VSIZE(USER) USER
  ----------- ------------------------------
   6 SYSTEM
  
  60.AVG(DISTINCT|ALL)
  all表示对所有的值求平均值,distinct只对不同的值求平均值
  SQLWKS> create table table3(xm varchar(8),sal number(7,2));
  语句已处理。
  SQLWKS> insert into table3 values('gao',1111.11);
  SQLWKS> insert into table3 values('gao',1111.11);
  SQLWKS> insert into table3 values('zhu',5555.55);
  SQLWKS> commit;
  SQL> select avg(distinct sal) from gao.table3;
  AVG(DISTINCTSAL)
  ----------------
   3333.33
  SQL> select avg(all sal) from gao.table3;
  AVG(ALLSAL)
  -----------
   2592.59
  61.MAX(DISTINCT|ALL)
  求最大值,ALL表示对所有的值求最大值,DISTINCT表示对不同的值求最大值,相同的只取一次
  SQL> select max(distinct sal) from scott.emp;
  MAX(DISTINCTSAL)
  ----------------
   5000
  62.MIN(DISTINCT|ALL)
  求最小值,ALL表示对所有的值求最小值,DISTINCT表示对不同的值求最小值,相同的只取一次
  SQL> select min(all sal) from gao.table3;
  MIN(ALLSAL)
  -----------
   1111.11
  63.STDDEV(distinct|all)
  求标准差,ALL表示对所有的值求标准差,DISTINCT表示只对不同的值求标准差
  SQL> select stddev(sal) from scott.emp;
  STDDEV(SAL)
  -----------
   1182.5032
  SQL> select stddev(distinct sal) from scott.emp;
  STDDEV(DISTINCTSAL)
  -------------------
   1229.951
  
  64.VARIANCE(DISTINCT|ALL)
  求协方差
  SQL> select variance(sal) from scott.emp;
  VARIANCE(SAL)
  -------------
   1398313.9
  65.GROUP BY
  主要用来对一组数进行统计
  SQL> select deptno,count(*),sum(sal) from scott.emp group by deptno;
   DEPTNO COUNT(*) SUM(SAL)
  --------- --------- ---------
   10 3 8750
   20 5 10875
   30 6 9400
  
  66.HAVING
  对分组统计再加限制条件
  SQL> select deptno,count(*),sum(sal) from scott.emp group by deptno having count(*)>=5;
   DEPTNO COUNT(*) SUM(SAL)
  --------- --------- ---------
   20 5 10875
   30 6 9400
  SQL> select deptno,count(*),sum(sal) from scott.emp having count(*)>=5 group by deptno ;
   DEPTNO COUNT(*) SUM(SAL)
  --------- --------- ---------
   20 5 10875
   30 6 9400
  67.ORDER BY
  用于对查询到的结果进行排序输出
  SQL> select deptno,ename,sal from scott.emp order by deptno,sal desc;
   DEPTNO ENAME SAL
  --------- ---------- ---------
   10 KING 5000
   10 CLARK 2450
   10 MILLER 1300
   20 SCOTT 3000
   20 FORD 3000
   20 JONES 2975
   20 ADAMS 1100
   20 SMITH 800
   30 BLAKE 2850
   30 ALLEN 1600
   30 TURNER 1500
   30 WARD 1250
   30 MARTIN 1250
   30 JAMES 950
  Oracle 最常用功能函数经典汇总
  来源:ChinaITLab 收集整理
  2004-6-14 10:58:00
  * SQL Group Function
  *
  s (num can be a column or ex
  pression)          
  (null values are ign
  *
  ored, default between distin
  ct and all is all)      
  ********************
  ***************
  ****************************
  ****************
  AVG([distinct or all] num)   
  -- average value
  COUNT(distinct or all] num)  
  -- number of values
  MAX([distinct or all
  ] num)   -- maximum value
  MAX([distinct or all] num)   
  -- minimum value
  STDDEV([distinct or
  all] num)  -- standard devi
  ation
  SUM([distinct or all
  ] num)   -- sum of values
  VARIANCE([distinct o
  r all] num) -- variance of v
  alues
  
  ********************************
  ***********************
  ************************
  * Miscellaneaous Functions :  
  *
  
  ********************
  ***************
  ****************************
  ****************
  DECODE(expr, srch1,
  return1 [,srch2, return2...]
  , default]
   -- if no search matches t
  he expression then the default is returned,
   -- otherwise,
  the first search that match
  es will cause
   -- the corres
  ponding return value to be r
  eturned
  DUMP(column_name [,fmt [,start_p
  os [, length]]])
  -- returns an
  column
  internal oracle format, used
  for getting info about a
  -- format options : 8 = oc
  tal, 10 = decimel, 16 = hex, 17 = characters
  -- return type
  codes : 1 = varchar2, 2 = n
  umber, 8 = long, 12 = date,
  --  23 = raw,
  24 = long raw, 69 = rowid,
  96 = char, 106 = mlslabel
  GREATEST(expr [,expr2 [, expr3...]]
  -- returns the largest val
  ue of all expressions
  LEAST(expr [,expr2 [, expr3...]]
  -- returns the
  smallest value of all expre
  ssions
  NVL(expr1 ,expr2
  -- if expr1 is not null, i
  t is returned, otherwise expr2 is returned
  SQLCODE
  -- returns sql error code
  query,
  of last error. Can not be used directly in
  -- value must
  be set to local variable fir
  st
  SQLERRM
  -- returns sql
  in query,
  error message of last error
  . Can not be used directly
  -- value must be set to lo
  cal variable first
  UID
  -- returns the user id of
  the user you are logged on as
  -- useful in s
  electing information from lo
  w level sys tables
  USER
  -- returns the
  user name of the user you a
  re logged on as
  USERENV('option')
  -- returns inf
  ormation about the user you
  are logged on as
  -- options : E
  NTRYID, SESSIONID, TERMINAL,
  LANGUAGE, LABEL, OSDBA
  --      (
  all options not available in
  all Oracle versions)
  VSIZE(expr)
  -- returns the number of b
  ytes used by the expression
  -- useful in s
  electing information about t
  able space requirements
  
  ********************
  ***************
  ****************************
  ****************
  * SQL Date Functions (dt represe
  *
  nts oracle date and time)          
  * (functions return
  *
  an oracle date unless otherw
  ise specified)        
  ********************************
  ***********************
  ************************
  ADD_MONTHS(dt, num)
  -- adds num months to
  dt (num can be negative)
  LAST_DAY(dt)    
   -- last day of month in
  month containing dt
  MONTHS_BETWEEN(dt1, dt2) -- retu
  dt2
  rns fractional value of months between dt1,
  NEW_TIME(dt, tz1, tz
  zone 2
  2)  -- dt = date in time zo
  ne 1, returns date in time
  NEXT_DAY(dt, str)    -- date
  etc..)
  of first (str) after dt (str = 'Monday',
  SYSDATE         -- present system date
  ROUND(dt [,fmt]     -- roun
  ds dt as specified by format fmt
  TRUNC(dt [,fmt]  
  -- truncates dt as spe
  cified by format fmt
  
  ********************************
  ***********************
  ************************
  * Number Functions :      
  *
  
  ********************************
  ***********************
  ************************
  ABS(num)       -- absolute
  value of num
  CEIL(num)      -- smallest integer > or = num
  COS(num)       -- cosine(n
  um), num in radians
  COSH(num)     
  -- hyperbolic cosine(num)
  EXP(num)      
  -- e raised to the num powe
  r
  FLOOR(num)      -- largest
  integer < or = num
  LN(num)       -- natural
  logarithm of num
  LOG(num2, num1)   -- logarith
  m base num2 of num1
  MOD(num2, num1)   -- remainde
  r of num2 / num1
  POWER(num2, num1) 
  -- num2 raised to the num1
  power
  ROUND(num1 [,num2]  -- num1 rou
  nded to num2 decimel places (default 0)
  SIGN(num)      -- sign of
  num * 1, 0 if num = 0
  SIN(num)      
  -- sin(num), num in radians
  SINH(num)      -- hyperbolic sine(num)
  SQRT(num)      -- square root of num
  TAN(num)       -- tangent(
  num), num in radians
  TANH(num)     
  -- hyperbolic tangent(num)
  TRUNC(num1 [,num2]  -- truncate
  num1 to num2 decimel places (default 0)
  
  ********************************
  ***********************
  ************************
  * String Functions,
  *
  String Result :      
  
  ********************************
  ***********************
  ************************
  (num)          -- ASCII
  character for num
  CHR(num)      
  -- ASCII character for n
  um
  CONCAT(str1, str2)   -- str1
  concatenated with str2 (same as str1||str2)
  INITCAP(str)    
  -- capitalize first lett
  er of each word in str
  LOWER(str)       -- str w
  ith all letters in lowercase
  LPAD(str1, num [,str2]) -- left
  spaces)
  pad str1 to length num with str2 (default
  LTRIM(str [,set]) 
   -- remove set from left
  side of str (default spaces)
  NLS_INITCAP(str [,nl
  s_val]) -- same as initcap f
  or different languages
  NLS_LOWER(str [,nls_
  val])  -- same as lower for
  different languages
  REPLACE(str1, str2 [,str3]) -- r
  eplaces str2 with str3 in str1
   --
  deletes str2 from str1 if str3 is omitted
  RPAD(str1, num [,str
  (default spaces)
  2])   -- right pad str1 to
  length num with str2
  RTRIM(str [,set]) 
  spaces)
   -- remove set from
  right side of str (default
  SOUNDEX(str)    
  -- phonetic represen
  tation of str
  SUBSTR(str, num2 [,n
  um1])  -- substring of str,
  starting with num2,
   --
  omitted)
  num1 characters (to end of str if num1 is
  SUBSTRB(str, num2 [,
  bytes
  num1]) -- same as substr bu
  t num1, num2 expressed in
  TRANSLATE(str, set1,
  set2) -- replaces set1 in
  str with set2
   --
  truncated
  if set2 is longer than set1, it will be
  UPPER(str)     
  -- str with all lett
  ers in uppercase
  
  ********************
  ***************
  ****************************
  ****************
  * String Functions,
  *
  Numeric Result :      
  
  ********************************
  ***********************
  ************************
  
  ASCII(str)           
  -- ASCII value of str
  INSTR(str1, str2 [,num1 [,num2]]
  ) -- position of num2th occurrence of
  
   -- str2 in str1, starting at num1
  
   -- (num1, num2 default to 1)
  INSTRB(str1, str2 [,num1 [num2]]
  ) -- same as instr, byte values for num1, num2
  LENGTH(str)    
   -- number of
  characters in str
  LENGTHB(str)          
  -- number of bytes in str
  NLSSORT(str [,nls_val])    
   -- nls_val byte value of str
  
  ********************************
  ***********************
  ************************
  * SQL Conversion Functions   
  *
  
  ********************************
  ***********************
  ************************
  CHARTOROWID(str)        
   -- converts str to ROWID
  CONVERT(str, chr_set2 [,chr_set1
  ]) -- converts str to chr_set2
  
  character set
  -- chr_set1
  default is the datbase
  HEXTORAW(str)   
   -- converts hex string va
  lue to internal raw values
  RAWTOHEX(raw_val)   -- convert
  s raw hex value to hex string value
  ROWIDTOCHAR(rowid) 
  -- converts rowid to 18 ch
  aracter string format
  TO_CHAR(expr [,fmt])
  fmt
  -- converts expr(date or n
  umber) to format specified by
  TO_DATE(str [,fmt])
   -- converts string to dat
  e
  TO_MULTI_BYTE(str)  -- convert
  s single byte string to multi byte string
  TO_NUMBER(str [,fmt]) -- convert
  s str to a number formatted by fmt
  TO_SINGLE_BYTE(str)
   -- converts multi byte st
  ring to single byte string
  
  ********************************
  ***********************
  ************************
  * SQL Date Formats 
  *
  
  
  ********************
  ***************
  ****************************
  ****************
  
  BC, B.C.    BC indicator
  AD, A.D.    AD indicator
  CC, SCC     Cent
  ury Code (SCC includes space
  or - sign)
  YYYY, SYYYY   4 digit year (SY
  YYY includes space or - sign)
  IYYY      4 digit ISO year
  Y,YYY      4 digit year with comma
  YYY, YY, or Y  last 3, 2, or 1
  digit of year
  YEAR, SYEAR   year spelled out
  (SYEAR includes space or - sign)
  RR       last 2 digits of
  year in prior or next century
  Q        quarter or year, 1 to 4
  MM       month - from 01 to 12
  MONTH      month spelled out
  MON       month 3 letter abbreviation
  RM       roman numeral for month
  WW       week of year, 1 to 53
  IW       ISO week of year
  , 1 to 52 or 1 to 53
  W        week of month, 1
  to 5 (week 1 begins 1st day of the month)
  D        day of week, 1 to 7
  DD       day of month, 1 to 31
  DDD       day of year, 1 to 366
  DAY       day of week spel
  led out, nine characters right padded
  DY       day abbreviation
  J        # of
  days since Jan 1, 4712 BC
  HH, HH12    hour of day, 1 to 12
  HH24      hour of day, 0 to 23
  MI       minute of hour, 0 to 59
  SS       second of minute, 0 to 59
  SSSSS      seco
  nds past midnight, 0 to 8639
  9
  AM, A.M.    am indicator
  PM, P.M.    pm indicator
  any puctuation punc
  tuation between format items
  , as in 'DD/MM/YY'
  any text    text between format items
  TH       conv
  erts 1 to '1st', 2 to '2nd',
  and so on
  SP       converts 1 to 'o
  ne', 2 to 'two', and so on
  SPTH      converts 1 to 'F
  IRST', 2 to 'SECOND', and so on
  FX       fill
  exact : uses exact pattern
  matching
  FM       fill mode : tog
  gles suppression of blanks in output
 

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