Fetch Parent class from Child class

How can I fetch user details from a child class?

Could you be more specific?
Do you mean that you have two tables in Backendless (Parent and Child) and Parent has relation on Child?
Did you consult this documentation?
https://backendless.com/documentation/data/ios/data_relations.htm

Yes, but you will have two different table.

Yes I have 2 tables in backendless and parent has relation on child (one to many), The documentation does not tell me how to access parent from child.

You could add in child class a 1:1 relation to object of the parent class

I neet a one to many relationship, I have attached a screenshot, How can I get the user details from the Users.events column?

“child of” is not a relation - it shows which other objects have this object as relation.

Ok. So what does that mean?

Relation is defined only one table. For example, there are two tables:

Order and OrderItem

Order contains a collection of OrderItem. This means Order will have a relation column which has OrderItem objects.

If you look at the OrderItem table, it will show (JUST FOR VISUALIZATION purposes) that it is OWNED by Order.

This is what you’re seeing when a column says “child of”