如何建立一个动态查询，该查询增加了迄今为止的天数，并使用标准API比较该日期与另一个日期？

您可以使用CriteriaBuilder＃function（）执行要添加

days

retentionDate

    Parameterexpression<String> dayUnit = builder.parameter(String.class, "dayUnit");    expression<DateTime> newDate = builder.function("DATEADD", DateTime.class, dayUnit, days, retentionDate);

完整的示例：

    CriteriaBuilder builder = entityManager.getCriteriaBuilder();    CriteriaQuery<B> cq = builder.createQuery(B.class);    Root<B> fromB = cq.from(B.class);    expression<DateTime> lastmodifiedDate = fromB.get(B_.lastmodifiedDate);    expression<DateTime> retentionDate = fromB.get(B_.a).get("retentionDate");    expression<Integer> days = fromB.get(B_.a).get("days");    Parameterexpression<String> dayUnit = builder.parameter(String.class, "dayUnit");    expression<DateTime> newDate = builder.function("DATEADD", DateTime.class, dayUnit, days, retentionDate);    cq.where(builder.greaterThanOrEqualTo(newDate, lastmodifiedDate));    TypedQuery<B> tq = entityManager.createQuery(cq.select(fromB));    tq.setParameter("dayUnit", "DAY");    List<B> results = tq.getResultList();

该查询将转换为SQL，如下所示：

select     b0_.id as id1_1_,     b0_.a_id as a_id3_1_,     b0_.lastmodified_date as lastmodi2_1_ from b b0_     cross join a a1_ where b0_.a_id=a1_.id     and DATEADD(?, a1_.days, a1_.retention_date)>=b0_.lastmodified_date