Re: Scientific Notation Problem

This WebDNA talk-list message is from

2001


It keeps the original formatting.
numero = 39265
interpreted = N
texte = Richard Kirsner wrote: > > The problem is that when I perform some [math] on the card number, the > result is in scientific notation and the card number doesn't survive the > reverse math that I perform in WebMerchant to view it. > Credit cards have too many digits to be stored as integers, so they are automatically uplifted to floats when you do math on them. The moral of this story is that credit card numbers are not not numbers so much as they are strings containing only numeric characters. Just like [cart] BTW.Johnp.s. why aren't you storing the numbers in the AccountNum fields; if you do that, you get WebCat's automatic checksum routine. They are stored on the server as plaintext but so what. If you cannot guarantee physical access to your server, you're screwed anyway.-- John Peacock Director of Information Research and Technology Rowman & Littlefield Publishing Group 4720 Boston Way Lanham, MD 20706 301-459-3366 x.5010 fax 301-429-5747------------------------------------------------------------- This message is sent to you because you are subscribed to the mailing list . To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to Web Archive of this list is at: http://search.smithmicro.com/ Associated Messages, from the most recent to the oldest:

    
  1. Re: Scientific Notation Problem (John Peacock 2001)
  2. Re: Scientific Notation Problem (Bob Minor 2001)
  3. Scientific Notation Problem (Richard Kirsner 2001)
Richard Kirsner wrote: > > The problem is that when I perform some [math] on the card number, the > result is in scientific notation and the card number doesn't survive the > reverse math that I perform in WebMerchant to view it. > Credit cards have too many digits to be stored as integers, so they are automatically uplifted to floats when you do math on them. The moral of this story is that credit card numbers are not not numbers so much as they are strings containing only numeric characters. Just like [cart] BTW.Johnp.s. why aren't you storing the numbers in the AccountNum fields; if you do that, you get WebCat's automatic checksum routine. They are stored on the server as plaintext but so what. If you cannot guarantee physical access to your server, you're screwed anyway.-- John Peacock Director of Information Research and Technology Rowman & Littlefield Publishing Group 4720 Boston Way Lanham, MD 20706 301-459-3366 x.5010 fax 301-429-5747------------------------------------------------------------- This message is sent to you because you are subscribed to the mailing list . To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to Web Archive of this list is at: http://search.smithmicro.com/ John Peacock

DOWNLOAD WEBDNA NOW!

Top Articles:

Talk List

The WebDNA community talk-list is the best place to get some help: several hundred extremely proficient programmers with an excellent knowledge of WebDNA and an excellent spirit will deliver all the tips and tricks you can imagine...

Related Readings:

Credit Card Number checking (1997) WebCat2b13 Command Reference Doc error (1997) authenticating a second user (1997) summ=T (2003) WebCat2b14MacPlugIn - [include] doesn't hide the search string (1997) Permissions with 3.06 Linux (2000) (1997) Trouble with Netscape (1998) I'm having trouble using [url][interpret][math] together inlookup (1997) Fun with Dates - finally resolved but.... (1997) Unable to view next 101-200 (1997) listing certain items in the orderfile (2002) Running _every_ page through WebCat-error.html (1997) Support ?? (1997) Banners (1997) New WebCatalog Version !!! (1997) Summing fields (1997) Kaaaaahhhhhhhnnnnnnn! (1997) Email SMTP Error 411 (2006) CountChars (2004)