Keywords to use in logical expressions.
The AND
keyword is used to combine two boolean conditions where both conditions must be true to yield a positive result.
This is the Conjunction within the boolean logical operations.
This function is SQL compatible. For more information about SQL compatibility, see our documentation.
Returns a Yes/No value that indicates if both conditions evaluate to true
.
The choose
construction can be used to check a multitude of conditions and return the expression that is part of the first condition that evaluates to be true.
The full construction should be created as displayed in the syntax, starting with choose
, ending with a default
expression and the end
keyword, and having 1 or more when ... then ...
expressions in between.
The Choose construct in WEM is comparable to Case or Switch statements in some programming languages. See wikipedia.
This function is SQL compatible. For more information about SQL compatibility, see our documentation.
Returns the value after the then
of the first condition that returns true.
If all conditions return false, then the value after default
is returned.
Don't forget the end
keyword.
All values after each then and default keyword must be of the same type to be returned.
The OR
keyword is used to combine two boolean conditions and will yield true if at least one condition evaluates to true.
This is the Disjunction within the boolean logical operations.
This function is SQL compatible. For more information about SQL compatibility, see our documentation.
Returns a Yes/No value that indicates if at least one condition evaluates to true
.
The If - Then - Else
construct can be used to make conditional parts in an expression.
Constructs can be "nested", just as long as each "nesting" has a block of matching If
, Then
and Else.
See wikipedia for more info on this construct.
The Choose construct can be used as an alternative when multiple conditions need to be checked: in many cases the Choose construct will be easier to read and understand.
This function is NOT SQL compatible. For more information about SQL compatibility, see our documentation.
Returns the value after the Then
if the condition in the If
statement returns true.
If the condition returns false, then the value after Else
is returned.
The NOT
keyword inverses (negates) a condition.
This is the Negation within the boolean logical operations.
This function is SQL compatible. For more information about SQL compatibility, see our documentation.
Returns the inversed condition.
If the condition evaluates to unknown, the inverse (NOT unknown) is also unknown.