9.RPAD和LPAD(粘貼字符)
RPAD? 在列的右邊粘貼字符
LPAD? 在列的左邊粘貼字符
SQL> select lpad(rpad('gao',10,'*'),17,'*')from dual;

LPAD(RPAD('GAO',1
-----------------
*******gao*******
不夠字符則用*來填滿

10.LTRIM和RTRIM
LTRIM? 刪除左邊出現(xiàn)的字符串
RTRIM? 刪除右邊出現(xiàn)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,從start開始,取count個
SQL> select substr('13088888888',3,8) from dual;

SUBSTR('
--------
08888888

12.REPLACE('string','s1','s2')
string?? 希望被替換的字符或變量
s1?????? 被替換的字符串
s2?????? 要替換的字符串
SQL> select replace('he love you','he','i') from dual;

REPLACE('H
----------
i love you

13.SOUNDEX
返回一個與給定的字符串讀音相同的字符串
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,默認為空格符

15.ABS
返回指定值的絕對值
SQL> select abs(100),abs(-100) from dual;

?ABS(100) ABS(-100)
--------- ---------
????? 100?????? 100

16.ACOS
給出反余弦的值
SQL> select acos(-1) from dual;

?ACOS(-1)
---------
3.1415927

17.ASIN
給出反正弦的值
SQL> select asin(0.5) from dual;

ASIN(0.5)
---------
.52359878

18.ATAN
返回一個數(shù)字的反正切值
SQL> select atan(1) from dual;

? ATAN(1)
---------
.78539816

19.CEIL
返回大于或等于給出數(shù)字的最小整數(shù)
SQL> select ceil(3.1415927) from dual;

CEIL(3.1415927)
---------------
????????????? 4

20.COS
返回一個給定數(shù)字的余弦
SQL> select cos(-3.1415927) from dual;

COS(-3.1415927)
---------------
???????????? -1

21.COSH
返回一個數(shù)字反余弦值
SQL> select cosh(20) from dual;

?COSH(20)
---------
242582598

22.EXP
返回一個數(shù)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
對給定的數(shù)字取整數(shù)
SQL> select floor(2345.67) from dual;

FLOOR(2345.67)
--------------
????????? 2345

24.LN
返回一個數(shù)字的對數(shù)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)
返回一個以n1為底n2的對數(shù)
SQL> select log(2,1),log(2,4) from dual;

?LOG(2,1)? LOG(2,4)
--------- ---------
??????? 0???????? 2

26.MOD(n1,n2)
返回一個n1除以n2的余數(shù)
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
按照指定的精度進行舍入
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
取數(shù)字n的符號,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
返回一個數(shù)字的正弦值
SQL> select sin(1.57079) from dual;

SIN(1.57079)
------------
?????????? 1

31.SIGH
返回雙曲正弦的值
SQL> select sin(20),sinh(20) from dual;

? SIN(20)? SINH(20)
--------- ---------
.91294525 242582598

32.SQRT
返回數(shù)字n的根
SQL> select sqrt(64),sqrt(10) from dual;

?SQRT(64)? SQRT(10)
--------- ---------
??????? 8 3.1622777

33.TAN
返回數(shù)字的正切值
SQL> select tan(20),tan(10) from dual;

? TAN(20)?? TAN(10)
--------- ---------
2.2371609 .64836083

34.TANH
返回數(shù)字n的雙曲正切值
SQL> select tanh(20),tan(20) from dual;

?TANH(20)?? TAN(20)
--------- ---------
??????? 1 2.2371609

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