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plsql函数大全

  1.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;
  
  TB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 出现的次数,默认为1;若I为负数,则从尾部开始搜索。
  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(如果start是负数,从尾部开始),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
  --------
  weatherwether
  
  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0SQL> 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
  ------
  200002SQL> 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 2004.05.10SQL> 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
  -----------
  9SQL>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 SMITHAAAAfKAACAAAAEqAAB AAAAfKAACAAAAEqAAB ALLENAAAAfKAACAAAAEqAAC AAAAfKAACAAAAEqAAC WARDAAAAfKAACAAAAEqAAD 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descSQL> 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 a30SQL> col dump_string for a50SQL> set lin 200SQL> 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--ACSQL> 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 userUSER 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,VSIZEISDBA 查看当前用户是否是DBA如果是则返回trueSQL> select userenv('isdba') from dual;
  
  USEREN------FALSESQL> select userenv('isdba') from dual;
  
  USEREN------TRUESESSION返回会话标志SQL> select userenv('sessionid') from dual;
  
  USERENV('SESSIONID')
  --------------------
  152ENTRYID返回会话人口标志SQL> select userenv('entryid') from dual;
  
  USERENV('ENTRYID')
  ------------------
  0INSTANCE返回当前INSTANCE的标志SQL> select userenv('instance') from dual;
  
  USERENV('INSTANCE')
  -------------------
  1LANGUAGE返回当前环境变量SQL> select userenv('language') from dual;
  
  USERENV('LANGUAGE')
  ----------------------------------------------------
  SIMPLIFIED CHINESE_CHINA.ZHS16GBKLANG返回当前环境的语言的缩写SQL> select userenv('lang') from dual;
  
  USERENV('LANG')
  ----------------------------------------------------
  ZHSTERMINAL返回用户的终端或机器的标志SQL> select userenv('terminal') from dual;
  
  USERENV('TERMINA
  ----------------
  GAOVSIZE(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;TB
  
  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   9400SQL> 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

posted on 2012-06-05 12:43 chen11-1 阅读(9723) 评论(1)  编辑  收藏 所属分类: oracle

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# re: plsql函数大全 2013-12-11 14:00 SOS

数字“0.7”如何变成文本后的显示仍然是“0.7”,而不是显示“.7”。如何通过SQL语句来实现?  回复  更多评论   


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