NLS_NUMERIC_CHARACTERS setting for decimal - oracle

Question

I have one db setup in a test machine and second in production machine. When I run:
select to_number('100,12') from dual
Then it gives error in test machine. However, this statement works quite fine in production machine.
Now, when I check for NLS_NUMERIC_CHARACTERS then I see ',' (comma) in both machine. Is there anywhere else I should be looking for the decimal setting?
Cheers!

Answer 1

You can see your current session settings by querying nls_session_parameters:
select value
from nls_session_parameters
where parameter = 'NLS_NUMERIC_CHARACTERS';
VALUE
----------------------------------------
.,
That may differ from the database defaults, which you can see in nls_database_parameters.
In this session your query errors:
select to_number('100,12') from dual;
Error report -
SQL Error: ORA-01722: invalid number
01722. 00000 - "invalid number"
I could alter my session, either directly with alter session or by ensuring my client is configured in a way that leads to the setting the string needs (it may be inherited from a operating system or Java locale, for example):
alter session set NLS_NUMERIC_CHARACTERS = ',.';
select to_number('100,12') from dual;
TO_NUMBER('100,12')
-------------------
100,12
In SQL Developer you can set your preferred value in Tool->Preferences->Database->NLS.
But I can also override that session setting as part of the query, with the optional third nlsparam parameter to to_number(); though that makes the optional second fmt parameter necessary as well, so you'd need to be able pick a suitable format:
alter session set NLS_NUMERIC_CHARACTERS = '.,';
select to_number('100,12', '99999D99', 'NLS_NUMERIC_CHARACTERS='',.''')
from dual;
TO_NUMBER('100,12','99999D99','NLS_NUMERIC_CHARACTERS='',.''')
--------------------------------------------------------------
100.12
By default the result is still displayed with my session settings, so the decimal separator is still a period.

Answer 2

Jaanna, the session parameters in Oracle SQL Developer are dependent on your client computer, while the NLS parameters on PL/SQL is from server.
For example the NLS_NUMERIC_CHARACTERS on client computer can be ',.' while it's '.,' on server.
So when you run script from PL/SQL and Oracle SQL Developer the decimal separator can be completely different for the same script, unless you alter session with your expected NLS_NUMERIC_CHARACTERS in the script.
One way to easily test your session parameter is to do:
select to_number(5/2) from dual;

Answer 3

To know SESSION decimal separator, you can use following SQL command:
ALTER SESSION SET NLS_NUMERIC_CHARACTERS = ', ';
select SUBSTR(value,1,1) as "SEPARATOR"
,'using NLS-PARAMETER' as "Explanation"
from nls_session_parameters
where parameter = 'NLS_NUMERIC_CHARACTERS'
UNION ALL
select SUBSTR(0.5,1,1) as "SEPARATOR"
,'using NUMBER IMPLICIT CASTING' as "Explanation"
from DUAL;
The first SELECT command find NLS Parameter defined in NLS_SESSION_PARAMETERS table. The decimal separator is the first character of the returned value.
The second SELECT command convert IMPLICITELY the 0.5 rational number into a String using (by default) NLS_NUMERIC_CHARACTERS defined at session level.
The both command return same value.
I have already tested the same SQL command in PL/SQL script and this is always the same value COMMA or POINT that is displayed. Decimal Separator displayed in PL/SQL script is equal to what is displayed in SQL.
To test what I say, I have used following SQL commands:
ALTER SESSION SET NLS_NUMERIC_CHARACTERS = ', ';
select 'DECIMAL-SEPARATOR on CLIENT: (' || TO_CHAR(.5,) || ')' from dual;
DECLARE
S VARCHAR2(10) := '?';
BEGIN
select .5 INTO S from dual;
DBMS_OUTPUT.PUT_LINE('DECIMAL-SEPARATOR in PL/SQL: (' || S || ')');
END;
/
The shorter command to know decimal separator is:
SELECT .5 FROM DUAL;
That return 0,5 if decimal separator is a COMMA and 0.5 if decimal separator is a POINT.

Answer 4

Best way is,
SELECT to_number(replace(:Str,',','')/100) --into num2
FROM dual;