I have a Parent and two children, with one to many relationship. I have defined the one to many relationships with set, everything works fine. But I want a list of children, so I tried with list. I get a error "Element "list" requires additional elements". When I looked at the documentation, I found that I need to add a index column. Do I need to add the index column in the database.
I don't want to add any new column in the database. In this case, am I forced to use a set and then convert my set to a List?


Thanks in advance.

A list requires the index so it knows where to position the element in the collection. So your answer is yes you will need the extra column if you want the collection mapped to a list.

Use a bag instead.