Availability
UPDATE command
Syntax
$WB-$NumericValueToBeSubtracted
Description
This is a form field value prefix for doing
mathematical operation of subtraction with values of fields of numeric type.
When WBSP engine receives a WBF_tablefieldname form field value
with this prefix for database table field of numeric type, instead of replacing
the old value with new one, it will subtract the new value from the existing one
(so new value stored in the database is
OldDatabaseTableFieldValue-NewFormValue)
Here's an example:
After running this example (and pressing the "Take 10 books" button), field Qty in updated record of table Titles will be decreased by 10.