Requirement: selector.operator.comparison.types

Only like type values can be compared. One exception is that it is valid to compare exact numeric values and approximate numeric values (the type conversion required is defined by the rules of Java numeric promotion). If the comparison of non-like type values is attempted, the value of the operation is false. If either of the type values evaluates to NULL, the value of the expression is unknown.


  • Section, Message Selector Syntax