decimal separator oracle

Question

I need to replace comma with point and then i need my value to be a number. So i wrote this:

select replace('12345,6789', ',' , '.') from dual --it works fine

but then I want to convert to_number that value and I get the error:

"invalid number"

Answer 1

The decimal separator is defined in your locale. Here it looks like it is ,. So you need not to do the replacement before converting your string:

select to_number('12345.6789') from dual --should work already

Or change your locale:

alter session  set NLS_NUMERIC_CHARACTERS= '.,';
select to_number('123'||'.'||'456') from dual;
select to_number(replace('12345,6789', ',' , '.')) from dual

Answer 2

The to_number() function uses the session's NLS_NUMERIC_CHARACTERS setting to decide how to interpret commas and periods. If you know your string will always have a comma as decimal separator you can override that as part of the call, using the optional third argument; although that does mean you have to specify the format model:

select to_number('12345,6789', '9999999999D9999', 'NLS_NUMERIC_CHARACTERS='',.''')
from dual;

TO_NUMBER('12345,6789','9999999999D9999
---------------------------------------
                             12345.6789

You don't need a separate replace() step.

You can also change the session's setting with ALTER SESSION SET NLS_NUMERIC_CHARACTERS=',.';, but you may not be able to control the setting in every client that has to run your code.