result coming twice , no conversion

[Mans]

Hi,
I have tried to convert upper to lower and lower to upper in single string it's coming but not with same.

select upper(substr('m aN',0,3))||lowe r(substr('maN', 3)) from dual;
Result:

UPPER(
------
MANn

but it should come like 'MAn'

[Rabbit]

That's because your first substring is returning 3 characters.

[Mans]

Rabbit, i am trying to get my result like convert upper to lower and lower to upper in same string
example : select 'AbcDEfgH' from dual;
and i am expecting result as
output: aBCdeFGh
all lower convert to upper and upper convert to lower.

[Rabbit]

If you're trying to flip the cases, then you can't do it with just upper and lower. You'll need to create a function to loop through each character.