group by的时候，看到的group by的结果字符是一样的，但是长度一样，trim之后还是这样

create table test(name varchar2(100), cnt number);

insert into test values('test', 1);

insert into test values('test'||chr(0), 1);

commit;

SQL> select * from test;

NAME CNT

-------------------- ----------

test 1

test 1

SQL> select name,length(name),sum(cnt) from test group by name;

NAME LENGTH(NAME) SUM(CNT)

-------------------- ------------ ----------

test 4 1

test 5 1

SQL> select trim(name) name,length(trim(name)),sum(cnt) from test group by name; --trim之后结果还是一样，可能name中有特殊字符

NAME LENGTH(TRIM(NAME)) SUM(CNT)

-------------------- ------------------ ----------

test 4 1

test 5 1

SQL> select trim(name) name,dump(name) name,length(trim(name)),sum(cnt) from test group by name; --有特殊字符

NAME NAME LENGTH(TRIM(NAME)) SUM(CNT)

-------------------- -------------------- ------------------ ----------

test Typ=1 Len=4: 116,101 4 1

,115,116

test Typ=1 Len=5: 116,101 5 1

,115,116,0