[转]ORACLE 字符串操作

1 字符串连接
 
SQL> select 'abc' || 'def' from dual;
'ABC'|
------
abcdef

2　小写
SQL>select lower('ABC012');
lower
--------
abc012

3　大写
select upper('abc012');

upper
--------
ABC012

4　 左补全
 
select lpad('abc', 5, '0');

lpad
-------
00abc

select lpad('abc', 5, '012');

lpad
-------
01abc
 
第3个参数为空时，缺省为space
 
select lpad('abc', 5);

lpad
-------
   abc

select lpad('abc', 5, ' ');

lpad
-------
   abc
 
5 　右补全
 
select rpad('abc', 5, '0');

rpad
-------
abc00

select rpad('abc', 5, '012');

rpad
-------
abc01
 
6　左空白删除

select ltrim('          abc');

ltrim
-------
abc
7　右空白删除
 
select ltrim('abc          ');

     ltrim
---------------
abc
 
 8　左右空白删除

select trim('          abc          ');

btrim
-------
abc

9　字符串替换
 
SQL> SELECT TRANSLATE('ababab' , 'a' , '1') FROM DUAL;
TRANSL
------
1b1b1b
 
10　取子字符串
 
SQL> select substr('abc012', 3, 2) from dual;
SU
--
c0
 
11　字符串长度
 
SQL> select length('abc012') from dual;
LENGTH('ABC012')
----------------
               6
12　 数字转化成字符串
 
SQL> select to_char(123456, '999,999,999,999') from dual;
TO_CHAR(123456,'
----------------
         123,456
 
13　字符串转化为数字
 
SQL> select to_number('123' || '456', '999999999999') from dual;
TO_NUMBER('123'||'456','999999999999')
--------------------------------------
                                123456

SQL> select to_number('123,456', '999,999,999,999') from dual;
TO_NUMBER('123,456','999,999,999,999')
--------------------------------------
                                123456