How to convert negative and comma separated values to numbers oracle? - sql

Question

I have values like -
43,042
- 1
44,889
35,224
- 1,000
17,683
and the data type is obviously varchar 2.
I have to put a condition in the column to select values above 5000 but I am unable to convert it to number due to presence of commas and negative signs.
How can I convert it to number to perform this check.
Thanks in advance.

Answer 1

try this
select to_number(replace(your_varchar_column,',','.'))
from your_table
where to_number(replace(your_varchar_column,',','.')) >5000

Answer 2

CREATE OR REPLACE function to_numeric(v in varchar2)
return number as
num number;
begin
num := to_number(v);
return num;
exception
when others then
return null;
end;
/

Answer 3

You can use to_number() with a suitable format model to convert your strings to numbers:
to_number(your_string, '999,999,999')
with the appropriate number of groups and group separators. I'm assuming, given that you're looking for values above 5000, that the commas represent group separators in your string and not decimal separators. It would be safer, to avoid relying on your session NLS settings, to be more explicit about it:
to_number(replace(your_string, ' '), '999G999G999', 'NLS_NUMERIC_CHARACTERS=''.,''')
The slight complication in your sample data is the presence of spaces in the strings too. You can use replace() to strip those out:
to_number(replace(your_string, ' '), '999,999,999')
so your condition could be:
where to_number(replace(your_string, ' '), '999,999,999') > 5000
or more safely:
where to_number(replace(your_string, ' '), '999G999G999', 'NLS_NUMERIC_CHARACTERS=''.,''')
> 5000
Demo with your strings coming from a CTE:
with t (n) as (
select '43,042 ' from dual
union all select '- 1' from dual
union all select '44,889' from dual
union all select '35,224' from dual
union all select '- 1,000' from dual
union all select '17,683' from dual
)
select n, to_number(replace(n, ' '), '999,999,999') as converted
from t
where to_number(replace(n, ' '), '999,999,999') > 5000;
N CONVERTED
------- ----------
43,042 43042
44,889 44889
35,224 35224
17,683 17683
or more safely:
with t (n) as (
select '43,042 ' from dual
union all select '- 1' from dual
union all select '44,889' from dual
union all select '35,224' from dual
union all select '- 1,000' from dual
union all select '17,683' from dual
)
select n, to_number(replace(n, ' '), '999G999G999', 'NLS_NUMERIC_CHARACTERS=''.,''')
as converted
from t
where to_number(replace(n, ' '), '999G999G999', 'NLS_NUMERIC_CHARACTERS=''.,''') > 5000;
Of course, you should not be storing numbers as string in the first place. Use the correct data type and you don't have to deal with this sort of issue. You also don't have to worry about string which are not in the format you expect, and which can therefore cause ORA-01722 errors for many reasons... even a number that doesn't have group separators, or has them in the wrong place, will error if you've stated they should be in certain places.