Databases Reference
In-Depth Information
Look closely. You'll see we are inserting the set modifier into our formula with the
use of the Dollar Sign Expansion syntax, which results in the exact same expression
as the original.
The reason for only storing the set modifier without the angle brackets in the variable
definition is to allow for the flexibility to include additional modifiers in the end
expression. For example, we can extend the set expression as follows:
Sum({$<$(vSetYTD), [Carrier's Operating Region] = {'Latin America'}>}
[# Departures Performed])
By adding expression-specific set modifiers, all of the other expressions using the
base set variable remain unaffected.
Furthermore, we can define all of the set expressions used for period comparisons so
that they are ready to be used when required from any given expression:
Variable name
Variable definition
vSetYTD
PeriodID = {"<=$(=Max(PeriodID))"},
Year = {$(=Max(Year))},
Quarter = ,
Month = ,
Period =
vSetQTD
PeriodID = {"<=$(=Max(PeriodID))"},
QuarterID = {$(=Max(QuarterID))},
Year = ,
Quarter = ,
Month = ,
Period =
vSetMTD
PeriodID = {$(=Max(PeriodID))},
Year = ,
Quarter = ,
Month = ,
Period =
vSetPreviousMonth
PeriodID = {$(=Max(PeriodID) - 1)},
Year = ,
Quarter = ,
Month = ,
Period =
