Oracle 函数大全
1.ASCII返回与指定的字符对应的十进制数;
SQL>selectascii('A')A,ascii('a')a,ascii('0')zero,ascii('')spacefromdual;
A A ZERO SPACE
------------------------------------
65 97 48 32
2.CHR给出整数,返回对应的字符;
SQL>selectchr(54740)zhao,chr(65)chr65fromdual;
ZHC
---
赵A
3.CONCAT连接两个字符串;
SQL>selectconcat('010-','88888888')||'转23' 高乾竞电话fromdual;
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>selectinitcap('smith')uppfromdual;
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>selectinstr('oracletraning','ra',1,2)instringfromdual;
INSTRING
---------
9
6.LENGTH返回字符串的长度;
SQL>selectname,length(name),addr,length(addr),sal,length(to_char(sal))from.nchar_tst;
NAME LENGTH(NAME)ADDR LENGTH(ADDR) SALLENGTH(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>selectlower('AaBbCcDd')AaBbCcDdfromdual;
AABBCCDD
--------
aabbccdd
8.UPPER返回字符串,并将所有的字符大写
SQL>selectupper('AaBbCcDd')upperfromdual;
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>selectlpad(rpad('gao',10,'*'),17,'*')fromdual;
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>selectltrim(rtrim(' gaoqianjing ',''),'')fromdual;
LTRIM(RTRIM('
-------------
gaoqianjing
11.SUBSTR(string,start,count)
取子字符串,从start开始,取count个
SQL>selectsubstr('13088888888',3,8)fromdual;
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>selectreplace('heloveyou','he','i')fromdual;
REPLACE('HELOVEYOU','HE','I')
------------------------------
iloveyou
13.SOUNDEX返回一个与给定的字符串读音相同的字符串
SQL>createtabletable1(xmvarchar(8));
SQL>insertintotable1values('weather');
SQL>insertintotable1values('wether');
SQL>insertintotable1values('gao');
SQL>selectxmfromtable1wheresoundex(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>selectabs(100),abs(-100)fromdual;
ABS(100)ABS(-100)
------------------
100 100
16.ACOS给出反余弦的值
SQL>selectacos(-1)fromdual;
ACOS(-1)
---------
3.1415927
17.ASIN给出反正弦的值
SQL>selectasin(0.5)fromdual;
ASIN(0.5)
---------
.52359878
18.ATAN返回一个数字的反正切值
SQL>selectatan(1)fromdual;
ATAN(1)
---------
.78539816
19.CEIL返回大于或等于给出数字的最小整数
SQL>selectceil(3.1415927)fromdual;
CEIL(3.1415927)
---------------
4
20.COS返回一个给定数字的余弦
SQL>selectcos(-3.1415927)fromdual;
COS(-3.1415927)
---------------
-1
21.COSH返回一个数字反余弦值
SQL>selectcosh(20)fromdual;
COSH(20)
---------
242582598
22.EXP返回一个数字e的n次方根
SQL>selectexp(2),exp(1)fromdual;
EXP(2) EXP(1)
------------------
7.38905612.7182818
23.FLOOR对给定的数字取整数
SQL>selectfloor(2345.67)fromdual;
FLOOR(2345.67)
--------------
2345
24.LN返回一个数字的对数值
SQL>selectln(1),ln(2),ln(2.7182818)fromdual;
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>selectlog(2,1),log(2,4)fromdual;
LOG(2,1) LOG(2,4)
------------------
0 2
26.MOD(n1,n2)返回一个n1除以n2的余数
SQL>selectmod(10,3),mod(3,3),mod(2,3)fromdual;
MOD(10,3) MOD(3,3) MOD(2,3)
---------------------------
1 0 2
27.POWER返回n1的n2次方根
SQL>selectpower(2,10),power(3,3)fromdual;
POWER(2,10)POWER(3,3)
---------------------
1024 27
28.ROUND和TRUNC
按照指定的精度进行舍入
SQL>selectround(55.5),round(-55.4),trunc(55.5),trunc(-55.5)fromdual;
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>selectsign(123),sign(-100),sign(0)fromdual;
SIGN(123)SIGN(-100) SIGN(0)
----------------------------
1 -1 0
30.SIN返回一个数字的正弦值
SQL>selectsin(1.57079)fromdual;
SIN(1.57079)
------------
1
31.SIGH返回双曲正弦的值
SQL>selectsin(20),sinh(20)fromdual;
SIN(20) SINH(20)
------------------
.91294525242582598
32.SQRT返回数字n的根
SQL>selectsqrt(64),sqrt(10)fromdual;
SQRT(64) SQRT(10)
------------------
83.1622777
33.TAN返回数字的正切值
SQL>selecttan(20),tan(10)fromdual;
TAN(20) TAN(10)
------------------
2.2371609.64836083
34.TANH
返回数字n的双曲正切值
SQL>selecttanh(20),tan(20)fromdual;
TANH(20) TAN(20)
------------------
12.2371609
35.TRUNC
按照指定的精度截取一个数
SQL>selecttrunc(124.1666,-2)trunc1,trunc(124.16666,2)fromdual;
TRUNC1TRUNC(124.16666,2)
---------------------------
100 124.16
36.ADD_MONTHS
增加或减去月份
SQL>selectto_char(add_months(to_date('199912','yyyymm'),2),'yyyymm')fromdual;
TO_CHA
------
200002
SQL>selectto_char(add_months(to_date('199912','yyyymm'),-2),'yyyymm')fromdual;
TO_CHA
------
199910
37.LAST_DAY
返回日期的最后一天
SQL>selectto_char(sysdate,'yyyy.mm.dd'),to_char((sysdate)+1,'yyyy.mm.dd')fromdual;
TO_CHAR(SYTO_CHAR((S
--------------------
2004.05.092004.05.10
SQL>selectlast_day(sysdate)fromdual;
LAST_DAY(S
----------
31-5月-04
38.MONTHS_BETWEEN(date2,date1)
给出date2-date1的月份
SQL>selectmonths_between('19-12月-1999','19-3月-1999')mon_betweenfromdual;
MON_BETWEEN
-----------
9
SQL>selectmonths_between(to_date('2000.05.20','yyyy.mm.dd'),to_date('2005.05.20','yyyy.dd'))mon_betwfromdual;
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>selectto_char(sysdate,'yyyy.mm.ddhh24:mi:ss')bj_time,to_char(new_time
2 (sysdate,'PDT','GMT'),'yyyy.mm.ddhh24:mi:ss')los_anglesfromdual;
BJ_TIME LOS_ANGLES
--------------------------------------
2004.05.0911:05:322004.05.0918:05:32
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>selectnext_day('18-5月-2001','星期五')next_dayfromdual;
NEXT_DAY
----------
25-5月-01
41.SYSDATE用来得到系统的当前日期
SQL>selectto_char(sysdate,'dd-mm-yyyyday')fromdual;
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>selectto_char(trunc(sysdate,'hh'),'yyyy.mm.ddhh24:mi:ss')hh,
2 to_char(trunc(sysdate,'mi'),'yyyy.mm.ddhh24:mi:ss')hhmmfromdual;
HH HHMM
--------------------------------------
2004.05.0911:00:002004.05.0911:17:00
42.CHARTOROWID将字符数据类型转换为ROWID类型
SQL>selectrowid,rowidtochar(rowid),enamefromscott.emp;
ROWID ROWIDTOCHAR(ROWID)ENAME
----------------------------------------------
AAAAfKAACAAAAEqAAAAAAAfKAACAAAAEqAAASMITH
AAAAfKAACAAAAEqAABAAAAfKAACAAAAEqAABALLEN
AAAAfKAACAAAAEqAACAAAAfKAACAAAAEqAACWARD
AAAAfKAACAAAAEqAADAAAAfKAACAAAAEqAADJONES