How to query my tables to give data in such a format?

Question

I have developed a structure to represent hierarchical data in in my db. Now I have 3 tables with relationship defined with each one.

How should I query my db to get the data in such a structure.

Query I have to get data from separate tables (Gives me all the users with product in the table) List discUsersConfs = newArrayList(ao.find(DiscUserConf.class, Query.select()));

(Gives me all the effects with users in the table)

List discEffectConfs = newArrayList(ao.find(DiscEffectConf.class, Query.select()));

How can I combine these queries to get the data in way I have shown the relationship in the below image. I am using Active Objects which is one of the ORM.

Answer 1

我通常会这样做。

select all from table1
while fetching{
     select again but from table 2 where user = (user from the table1)
          ...and so on..

 }

这是一个问题，它有多个解决方案。我的方法的问题是，对于每个更深层次，您必须提供更多表并手动将它们添加到代码