.net - 您是否知道在使用 SetFirstResult 和 SetMaxResults 时如何在不使用 ResultTransformer 的情况下获得不同的结果集？

Question

当我使用 SetFirstResult 和 SetMaxResult 时，如果查询已连接，则结果具有重复结果而不是唯一结果。

然后我将所有类型的 Distinct 助手用于标准 api。但它不会过滤整个结果集，它只会过滤分页结果。

我怎样才能克服这个问题？

谢谢

Answer 1

我找到了 hacky thing to overcome这个问题。

The only "workaround" for this that I've been able to come up with is to issue two queries from the criteria same criteria object. The first one gets the id's the second one is contrained to the ids.

//set up crtieria as you wish, including pagination myCriteria = doStuffToSetupCriteria(); myCriteria.setFirstResult((page-1)*itemsPerPage); myCriteria.setMaxResults(itemsPerPage);

//get the list if primary keys myCriteria.setProjection(Projections.distinct(Projections.property("myAllias.id")); List ids = gacc.list();

//now add the id's into the restriction myCriteria.add(Restrictions.in("myAlias.id, ids));

//clean up from the last critiera run gacc.setProjection(null); gacc.setFirstResult(0); gacc.setMaxResults(Integer.MAX_VALUE);

//your results List objects = gacc.list()

A little hacky I agree, but the only acceptable soltion I could find given this limitiation.