Question

I am using Hibernate. I have the following SQL query. I have to convert it to criteria. How can I achieve it?

SELECT DISTINCT username 
    FROM usertable 
    WHERE user_id in (SELECT DISTINCT user_id FROM someother_table);

Answer 1

This should do what you’re looking for if you’ve mapped “user_id” as property and didn’t map any relationships (if you did the right property might be “myEntity.user.id” instead of “myEntity.user_id”)

Criteria criteria = getSession().createCriteria(MyEntity.class, "myEntity");

//setting projection to distinct(myEntity.username)
criteria.setProjection(Projections.distinct(Projections.property("myEntity.username")));

DetachedCriteria subCriteria = DetachedCriteria.forClass(MyOtherEntity.class, "myOtherEntity");
subCriteria.setProjection(Projections.distinct(Projections.property("myOtherEntity.user_id")));

criteria.add(Subqueries.propertyIn("myEntity.user_id", subCriteria));