单向一对多关系的条件查询

我终于找到了答案，只需使用两个

roots

    CriteriaBuilder cb = entityManager.getCriteriaBuilder();    CriteriaQuery<POS> cq = cb.createQuery(POS.class);    Root<POS> posRoot = cq.from(POS.class);    Root<Supplier> supplierRoot = cq.from(Supplier.class);    cq.where(cb.and(         cb.equal(supplierRoot.get(Supplier_.suppliertId), supplierId),         cb.equal(posRoot.get(POS_.posId), posId)));    cq.select(posRoot);