Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
381 views
in Technique[技术] by (71.8m points)

sql - Using Hibernate's Criteria and Projections to Select Multiple Distinct Columns

Using Hibernate's Criteria, I want to execute the equivalent of:

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

I thought doing the following would yield the results I wanted:

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

But, what this actually does is execute something like:

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

Which throws an error, obviously.

Other than not using Criteria, is there a solution for this?

Thanks,

Brandon

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)
ProjectionList projList = Projections.projectionList();
projList.add(Projections.property("id.state"));
projList.add(Projections.property("id.uspsCity"));
criteria.setProjection(Projections.distinct(projList));

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...