使用Hibernate的标准和预测来选择多个不同的列

Question

使用Hibernate的Criteria,我想执行相当于:

select distinct uspscity, state from citycomplete where USPSCITY = 'HOUSTON'

我认为做以下操作会产生我想要的结果:

ProjectionList projList = new ProjectionList();
projList.add(Projections.distinct(Projections.property("id.state")));
projList.add(Projections.distinct(Projections.property("id.uspsCity")));
criteria.setProjection(projList);

但是,这实际上做的是执行类似的事情:

select distinct uspscity, distinct state from citycomplete where USPSCITY = 'HOUSTON'

显然,这会引发错误.

除了不使用Criteria之外,还有解决方案吗？

谢谢,

布兰登

Answer 1

ProjectionList projList = Projections.projectionList();
projList.add(Projections.property("id.state"));
projList.add(Projections.property("id.uspsCity"));
criteria.setProjection(Projections.distinct(projList));