Question

I was looking at the MDD function documentation and wondered if there is the possibility to have some kind of control flow inside MDD functions.

In a type definition there’s a type that has a pointer parameter to other entities of its type which might be null. I’d like to be able to iterate through them until this parameter is null while extracting data from another parameter.

Any idea on how to achieve this?

Answer 1

Since the MDD functions are based on HQL you can use most of the expressions available in it.

For the control flow you have a SQL-like CASE statements.

For example:

getSomeData() { CASE WHEN (pointer1 <> nil) 
                     THEN CASE WHEN (pointer1.pointer2 <> nil)
                               THEN pointer1.potiner2.field3
                               ELSE pointer1.field2 END
                     ELSE field1 END }