About Static Variables

Use a static variable when you need a variable with a fixed value.

For example, suppose you want to create an expression to group times of day into different day segments. If Prime Time were one of those segments and corresponded to the hours between 5:00 PM and 10:00 PM, you could create a CASE statement like the following:

CASE WHEN "Hour" >= 17 AND "Hour" < 23 THEN 'Prime Time' WHEN... ELSE...END

Hour is a logical column, mapped to a timestamp physical column using the date-and-time Hour(<<timeExpr>>) function.

Instead of entering the numbers 17 and 23 into this expression as constants, you could create and use a static variable named prime_begin, set the variable's value to 17, and then create another variable named prime_end and set the variable's value to 23.

When you create a static variable, you must include a default value. You can set the Value field with a number, character, date, time, or timestamp value. Or you can use the Expression Editor to insert the Date, Time, and TimeStamp constants into an expression.