How To Build Query With Selecting By Value Of Foreign Object's Field

What is the best way for querying by using the value of foreign object's field? Suppose I have these three classes. UnitResult class which describes amount of Units: @DatabaseTable

Solution 1:

So how can I query all UnitResult where Unit type is UnitType.JUICES?

The way to do this in ORMLite is to use the `Where.in(...) with a sub-query:

// setup oursub-queryontheUnittablefirstQueryBuilder<Unit,Integer> uQb = unitDao.queryBuilder();
uQb.where().eq(Unit.TYPE_FIELD_NAME, UnitType.JUICES);
// outer query on UnitResult table
QueryBuilder<UnitResult,Integer> urQb = unitResultDao.queryBuilder();
// in using the sub-queryurQb.where().in(UnitResult.UNIT_COLUMN_NAME, uQb);
List<UnitResult> results = urQb.query();