deleting objects in relations. Searching objects in the opposite direction

[TomekK]

Would you please give me a tip about relations in OrientDB and ObjectApi?

Suppose that there are 2 classes

Public class Person {

     Private String name;

     ...

}

Public class Group {

    @ManyToMany

     Private Set <Person> members;

     ...

}

 

And in DB  an object 'myGroup' with linkset to persons_1, person_2

Now we want to remove person_1.

How to prevent situation where members include link to deleted object?

Does OrientDB have a built-in mechanism to remove link from members in this situation?

Is it possible to force OrientDB to return an exception during attempt to remove person_1?

What is the best way to find all group of person_2? Do I need to use sth like "select from group where ..." or is another way?

Above is easy but we can have A with links to B, and B links to C etc. It's easy to move from A to C but what the best way the search objects in the opposite direction?