Oracle 9i - passing a string as parameter when integer is required yet

Question

Dear all;
I am trying to fix this problem with a limited amount effort and also prevent redesigning it as well. I know it is completely wrong but it was done by a past developer and I am just trying to make a simple twick to it. I will try to explain my current problem so please bear with me
I have a table with a field called SN which is number type field, I have a select statement similar to this below
select stype from tbl_one where sn = 1ok, the select statement works for numbers and numbers with dash(e.g 03-2). In the case of numbers with dash, it returns null which is okay now, I am having a bit of problems where sometimes the user entry is a an actual string like this (cat). Now the select statement isnt going to work for this case because I am going to get a Ora-00904 - invalid identifier error.
The solution I had in mind is first use a regular expression to determine whether the parameter is a string or a numeric value and if it is a numer value pass it as a parameter to the select statment if not, then just return null in the select statement. However, since I am using oracle 9i I cant use regualr expression is there any suitable sql statment i can use in replacement of a regular expression or any other ideas.
All help is appreciated. Thank you.

Answer 1

Hi,
user13328581 wrote:
... the select statement works for numbers and numbers with dash(e.g 03-2). That's actually not a number with a dash. That's a subtraction operation involving two numbers, 03 (which is the same as 3) and 2. 3 - 2 = 1, so it's the same as typing 1.
The solution I had in mind is first use a regular expression to determine whether the parameter is a string or a numeric value and if it is a numer value pass it as a parameter to the select statment if not, then just return null in the select statement. However, since I am using oracle 9i I cant use regualr expression is there any suitable sql statment i can use in replacement of a regular expression or any other ideas.If you just want to see if the string s contains anything other than a digit, use
LTRIM ( s
      , '0123456789'
      )  IS NOT NULLThe condition above will be TRUE when s contains anything other than a digit.
If you want to check for signs, decimal points, and scientific notation, then see this thread:
How to identify if a Varchar2 string has a-z characters?
for a user-defined function.
Edited by: Frank Kulash on Apr 21, 2011 11:28 AM