ORA-01722: invalid number when performing query

Question

Hi,
I am running SQL Developer on a laptop (XP Pro) accessing Oracle Applications
Product Version     11.5.10.2
Platform     IBM SP AIX
OS Version     AIX
Database     9.2.0.7.0
Support ID     14460365
If I run the following query it works fine -
select
mtrh.request_number
,to_number(mtrh.request_number)
from
mtl_txn_request_headers mtrh
where
to_number(mtrh.request_number) = 135060
and mtrh.request_number = '135060' -- works with this line in!!!!
however if I comment out the last line I get
An error was encountered performing the requested operation :
ORA-01722: invalid number
The field request_number is defined as varchar2(30)
It seems that there is something strange about the way it handles to_number in where clauses.
Thanks
Mick Sulley

Answer 1

You have an invalid number in request_number. If you add "and mtrh.request_number = '135060' ", the result set will be reduced to only those rows which have 135060 in the column and the to_number() will work. WIthout that row, it does to_number(request_number) for all rows in order to identify the one you want. When it comes across a request_number column which contains an invalid number it reports an error.
<preach>
If request_number is a number then it should be stored in a number column. If it isn't, don't try an convert it to a number.
</preach>