Sub query support for IN and NOT IN

[fehays]

Inner Joins (IN sub query)

Q query = new Q(Account.SObjectType)
    .addSubquery(new Q('Contacts').selectFields(new Set<String> {'Name'}))
    .add(Q.condition('Id').isIn(new Q(Contact.SObjectType).selectFields(new Set<String> {'AccountId'})));

System.debug(query.build());
//SELECT (SELECT Name FROM Contacts) FROM Account WHERE Id IN (SELECT AccountId FROM Contact)