SQL> select rtrim('abc1','1234567890') from dual;RTRIM('ABC1','1234567890')
--------------------------
abcSQL> select rtrim('abc11','1234567890') from dual;RTRIM('ABC11','1234567890')
---------------------------
abcSQL> select rtrim('dft123','1234567890') from dual;RTRIM('DFT123','1234567890')
----------------------------
dftSQL> select rtrim('dd1','1234567890') from dual;RTRIM('DD1','1234567890')
-------------------------
dd
--------------------------
abcSQL> select rtrim('abc11','1234567890') from dual;RTRIM('ABC11','1234567890')
---------------------------
abcSQL> select rtrim('dft123','1234567890') from dual;RTRIM('DFT123','1234567890')
----------------------------
dftSQL> select rtrim('dd1','1234567890') from dual;RTRIM('DD1','1234567890')
-------------------------
dd
LTrim(char, set) / RTrim(char, set)
把c1中最左边的字符去掉,使其第一个字符不在set中,如果没有set,那么c1就不会改变。