Hibernate criterion Projection alias not being used

hibernate, java

Solution

You need to give the entire criteria an alias, then you can create other aliases that actually get used. What is strange is that the aliases get turned into `y0_` instead of the other way around.

return sessionFactory.getCurrentSession()
    .createCriteria(PersonProgramActivity.class, "ppa")
    .setProjection(Projections.projectionList()
        .add(Projections.alias(Projections.sum("numberOfPoints"), "ppa.numberOfPoints"))
        .add(Projections.groupProperty("person.id")))
    .setFirstResult(start)
    .setFetchSize(size)
    .addOrder(Order.desc("ppa.numberOfPoints"))
    .list();

Generates the following SQL:

select
    sum(this_.number_of_points) as y0_,
    this_.person_id as y1_
from
    PERSON_PROGRAM_ACTIVITY this_
group by
    this_.person_id
order by
    this_.y0_ desc

Problem

Do Hibernate Projection aliases even work? I could swear it just doesn't. At least, it doesn't do what I would expect it to do. Here is the java: ``` return sessionFactory.getCurrentSession() .createCriteria(PersonProgramActivity.class) .setProjection(Projections.projectionList() .add(Projections.alias(Projections.sum("numberOfPoints"), "number_of_points")) .add(Projections.groupProperty("person.id"))) .setFirstResult(start) .setFetchSize(size) .addOrder(Order.desc("numberOfPoints")) .list(); ``` Here is the SQL that it generates: ``` select sum(this_.number_of_points) as y0_, this_.person_id as y1_ from PERSON_PROGRAM_ACTIVITY this_ group by this_.person_id order by this_.number_of_points desc ``` It doesn't seem to use the alias at all. I would think setting the alias would mean that `sum(this_.number_of_points)` would be aliased as `number_of_points` and not `y0_`. Is there some trick I am missing? Thanks.

Original source