Question

I have tables A, B, C, D, E and I’m doing inner join across them.
I need only partial data from results. For example, I need A.name column, D.phoneNumber column.

I’m using the method join().

How should I handle the result? Should I go through all my classes, to get all the data I need? If yes, what is a simple way to do this, because going through all of that seems a bit complicated.

Should I create a class just for result and somehow map the result to it?

Answer 1

According to the ORMlite documentation you can only use join statement with the tables connected via foreign object field.

So the first approach as I see it is to use foreign object and retreive all the values you need. For example if you query you tables A and B with

QueryBuilder<A, Integer> aqb = aDao.queryBuilder();
QueryBuilder<B, Integer> bqb = bDao.queryBuilder();
List<A> results = aqb.join(bqb).query();

for (A a : results){
    String name = a.getName();
    String phone = a.getB().getPhone();
}

whereas A and B classes looks something like this:

....
public class A{
....
    @DatabaseField
    private String name;

    @DatabaseField(foreign = true, foreignAutoRefresh = true)
    private B b;
....        
    public B getB(){
        return b;
    }
....
    public String getName(){
        return name;
    }
}

....
public class B{
....
    @DatabaseField
    private String phone;

    public String getPhone(){
        return phone;
    }
}

I’m not sure about exactly this code will work, I just wanted to describe the idea.

As I know you can’t query for the multiple tables at once.

See the related ORMLite documentation.
Join statements have been supported since version 4.42 of the library.