Kbase 21104: How To Do An 'Exclusive OR' (XOR)
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
16/10/2008 |
|
Status: Unverified
GOAL:
How to use an Exclusive OR (XOR).
FIX:
An XOR, called Exclusive OR, will return TRUE when each logical expression has a different logical value. That is:
A B A XOR B
----- ----- -------
False False False
False True True
True False True
True True False
Progress has three logical operators: AND, OR and NOT. Combining them users can do an XOR:
XOR = (OR) AND (NOT AND).
The next example displays all invoice records if the invoice.amount is less than 1000 OR the invoice.total-paid is less than 1000. It will exclude records where the invoice.amount and invoice.total-paid are both less than 1000.
FOR EACH invoice WHERE
(amount < 1000 OR total-paid < 1000) AND NOT
(amount < 1000 AND total-paid < 1000):
display invoice-num amount total-paid.
END.