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B25__Quantity__c + SUM(overlappingReservations, B25__Quantity__c) > SUM(matchingAvailabilities, capacity__c) OR COUNT(overlappingReservations AS rsv, rsv.Gender__c != Gender__c) > 0
Reservations are not allowed to be double booked and when the running user doesn’t have the permission to “overrule double bookings”
COUNT(overlapping_reservations) > 0 and $Permission.B25__ALLOW_DOUBLE_BOOKING == false
Not supported in this beta:
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