Warning Constraint Example: Scheduling Tours to Unstable Destinations

The Travel Agency schedules tours to many exotic destinations. Sometimes, a destination is not considered to be stable, politically or economically. It is not recommended then to schedule a tour to this destination. However, it is the participant that decides whether to take the risk.

1.	Define a new message categorie, and do not select the System check box:

Category: Constraint Warning

2.	Define a new system message:

Code: 1

Category: Constraint Warning

Name: UNSTABLE_DESTINATION

Message: (Destination) is currently considered an unstable region.

Parameter: Destination

Seqno: 1

3.	Define a constraint:

Name: WARNING_UNSTABLE_DESTINATION

SQL Statement:

INVOKE    RulesEngine.MessageLanguage
WITH
SELECT    'Constraint Warning'
,         'UNSTABLE_DESTINATION'
,         'WARNING'
,         destination
FROM      schedtour
WHERE     destination IN ( 'PAKISTAN','BALI' )

Do not specify a constraint message: the component takes care of the message.