Relational routine
The Relational routine contains several functions which allow you to check affirmations based on boolean values.
You can access these functions by double-clicking the Relational node under the system routines folder in the Repository tree view.
| Function | Description | Syntax | 
|---|---|---|
| ISNULL | Checks if the variable provided is a null value. It returns true if the value is NULL and false if the value is not NULL.  | 
                  Relational.ISNULL(variable) | 
| NOT | Returns the complement of the logical value of an expression. | Relational.NOT(expression) | 
| isNull | Checks if the variable provided is a null value. It returns 1 if the value is NULL and 0 if the value is not NULL.  | 
                  Relational.isNull(variable) | 
To check the Relational routine, you can use the
            ISNULL function, along with a tJava component,
         for
         example:
      String str = null;
System.out.println(Relational.ISNULL(str));In this example, the test result is displayed in the Run view: