oracle函数大全:Oracle SQL内置函数大全(一)来源: 发布时间:星期日, 2009年2月22日 浏览:4次 评论:0
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SQL中单记录
1.ASCII
返回和指定对应十进制数;
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;
SQL> select chr(54740) zhao,chr(65) chr65 from dual;
ZH C
-- -
赵 A
3.CONCAT
连接两个串;
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
返回串并将串第个字母变为大写;
SQL> select initcap('smith') upp from dual;
UPP
-----
Smith
5.INSTR(C1,C2,I,J)
在个串中搜索指定,返回发现指定位置;
C1 被搜索串
C2 希望搜索串
I 搜索开始位置,默认为1
J 出现位置,默认为1
SQL> select instr('Oracle traning','ra',1,2) in from dual;
INSTRING
---------
9
6.LENGTH
返回串长度;
SQL> select name,length(name),addr,length(addr),sal,length(to_char(sal)) from .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
返回串,并将所有小写
SQL> select lower('AaBbCcDd')AaBbCcDd from dual;
AABBCCDD
--------
aabbccdd
8.UPPER
返回串,并将所有大写
SQL> select upper('AaBbCcDd') upper from dual;
UPPER
--------
AABBCCDD
9.RPAD和LPAD(粘贴)
RPAD 在列右边粘贴
LPAD 在列左边粘贴
SQL> select lpad(rpad('gao',10,'*'),17,'*')from dual;
LPAD(RPAD('GAO',1
-----------------
*******gao*******
不够则用*来填满
10.LTRIM和RTRIM
LTRIM 删除左边出现串
RTRIM 删除右边出现串
SQL> select ltrim(rtrim(' gao qian jing ',' '),' ') from dual;
LTRIM(RTRIM('
-------------
gao qian jing
11.SUBSTR(,start,count)
取子串,从start开始,取count个
SQL> select substr('13088888888',3,8) from dual;
SUBSTR('
--------
08888888
12.REPLACE('','s1','s2')
希望被替换或变量
s1 被替换串
s2 要替换串
SQL> select replace('he love you','he','i') from dual;
REPLACE('HELOVEYOU','HE','I')
------------------------------
i love you
13.SOUNDEX
返回个和给定串读音相同串
SQL> create table table1(xm varchar(8));
SQL> insert o table1 values('weather');
SQL> insert o table1 values('wether');
SQL> insert o table1 values('gao');
SQL> select xm from table1 where soundex(xm)=soundex('weather');
XM
--------
weather
wether
14.TRIM('s' from '')
LEADING 剪掉前面
TRAILING 剪掉后面
假如不指定,默认为空格符
15.ABS
返回指定值绝对值
SQL> select abs(100),abs(-100) from dual;
ABS(100) ABS(-100) --------- --------- 100 100 16.ACOS 给出反余弦值 SQL> select acos(-1) from dual; ACOS(-1) --------- 3.1415927 17.ASIN 给出反正弦值 SQL> select asin(0.5) from dual; ASIN(0.5) --------- .52359878 18.ATAN 返回个数字反正切值 SQL> select atan(1) from dual; ATAN(1) --------- .78539816 19.CEIL 返回大于或等于给出数字最小整数 SQL> select ceil(3.1415927) from dual; CEIL(3.1415927) --------------- 4 20.COS 返回个给定数字余弦 SQL> select cos(-3.1415927) from dual; COS(-3.1415927) --------------- -1 21.COSH 返回个数字反余弦值 SQL> select cosh(20) from dual; COSH(20) --------- 242582598 22.EXP 返回个数字en次方根 SQL> select exp(2),exp(1) from dual; EXP(2) EXP(1) --------- --------- 7.3890561 2.7182818 23.FLOOR 对给定数字取整数 SQL> select floor(2345.67) from dual; FLOOR(2345.67) -------------- 2345 24.LN 返回个数字对数值 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) 返回个以n1为底n2对数 SQL> select log(2,1),log(2,4) from dual; LOG(2,1) LOG(2,4) --------- --------- 0 2 26.MOD(n1,n2) 返回个n1除以n2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n1n2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 返回个数字正弦值 SQL> select sin(1.57079) from dual; SIN(1.57079) ------------ 1 0
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