Oracle functions
Examples of function in oracle 9i,pls check the defination of them if not clear about it.
1.select ascii('A') A,ascii('a') a,ascii(0) zero,ascii(' ') space from dual
65 97 48 32
2.select chr(54740) zhao,chr(65) chr65 from dual
赵 A
3.select concat('0557-','88888888')||'-1234' tel from dual
0557-88888888-1234
4.select initcap('smith') upp from dual
Smith
5.select instr('oracle traning','ra',1,1) instring1,instr('oracle traning','ra',1,2) instring2 from dual
2 9
6.select length('length') from dual
6
7.select lower('ABcCdD') from dual
abccdd
8.select upper('ABcCdD') from dual
ABCCDD
9.select lpad(rpad('gao',10,'*'),17,'&') from dual
&&&&&&&gao*******
10.select rtrim('oracleleleylele','le') from dual
oracleleley
select ltrim('leeleleoracle','le') from dual
oracle
11.select substr('oracle',2,2) from dual
ra
12.select replace('No one love you','No one','I') from dual
I love you
13.select trim(' a bc d d ') from dual
a bc d d
14.select abs(-1) from dual
1
15.select acos(-1) from dual
3.14159265358979
16.select ceil(7.8) from dual
8
17.select exp(1),exp(2) from dual
2.71828182845905 7.38905609893065
18.select floor(7.8) from dual
7
19.select log(2,1),log(2,8) from dual
0 3
20.select mod(2,1),mod(2,8),mod(5,3) from dual
1 0 2 2
21.select power(2,10) from dual
1024
22.select trunc(55.4), trunc(55.5), trunc(-5.4), trunc(-5.5) from dual
55 55 -5 -5
select trunc(123.123,-2),trunc(123.123,2) from dual
100 123.12
select round(55.4), round(55.5), round(-5.4), round(-5.5) from dual
55 56 -5 -6
23.select sign(10),sign(-10),sign(0) from dual
1 -1 0
24.select sqrt(10),sqrt(9),sqrt(0) from dual
3.16227766016838 3 0
25.select to_char(add_months(to_date('200910','yyyymm'),2),'yyyymm') from dual
200912
26.select last_day(sysdate) from dual
2009-12-31 10:27:38
27.select months_between(to_date('19990202','yyyymmdd'),to_date('19990902','yyyymmdd')) from dual
-7
28.select next_day(to_date('20091218','yyyymmdd'),'星期五') from dual
2009-12-25
29.select rowid,rowidtochar(rowid),a.log_content from t_log a
AAAHYnAAJAAAAD4AAA AAAHYnAAJAAAAD4AAA haha
AAAHYnAAJAAAAD4AAB AAAHYnAAJAAAAD4AAB hahaho
30.select to_multi_byte('gao') from dual
ｇａｏ
31.select to_number('2012') from dual
2012
32.select greatest('2012','2000','2011') from dual
2012
33.select least('2012','2000','2011') from dual
2000
34.select user,uid from dual
JIL 59
35.select userenv('language') from dual
SIMPLIFIED CHINESE_CHINA.ZHS16GBK
36.select (case when 1=2 then 0 else 1 end) from dual
1
37.select nvl(null,2) from dual
2
select nvl(1,2) from dual
1
38.select decode(sign(1+2),-1,2,1,0) from dual
0
select decode(sign(1-2),-1,2,1,0) from dual
2