I have two sets of data types and associated tables: brother's and sisters. Each data type has a parent id and contains a collection of siblings of the opposite gender. Therefore, there is a many-to-many relationship between the brothers and sisters. This relationship is based on them sharing a common parentId attribute -- i.e. I am not using a join table

I have read through the documentation and examples. All many-to-many associations that I have come across in hibernate require a join table in order to complete the many-to-many mapping. However, I do not want to maintain these relationships in a seperate join table. All of the information required for forming the relationship is in the shared parentId. I would like to have the ability to query and initialize collections of the associated siblings by using the commonParentId.

Is there a simple way to map a many-to-many relationship based on a common attribute without requiring a join table?

Wow, your post is quite bold

It seems to me that since you have a parentId in each these that you probably have a PARENT table. This means the parent table IS the join table. In that sense, the parent has a one-to-many on each type of child. Then you can derive the many-to-many you discussed by accessing their parent.

Now, the problem with what I just mentioned is that only one parent can exist so you'll have to work with that a bit.