Question

I’m wondering if anybody knows how to get multiple counts from a single query using hibernates criteria query?

I have the following query.

List<PurchaseRequest> prs = this.session.createCriteria(PurchaseRequest.class).list();

within PurchaseRequest, I have a column called current_state. I’d like to query all the PurchaseRequest rows and group the current_states together so I can get a total count of each current_state.

States look like this, creator, authorizer, assignor. etc.

Answer 1

Try this:

Criteria criteriaPurchaseRequest=this.session.createCriteria(PurchaseRequest.class);

ProjectionList projectionList = Projections.projectionList();
projectionList.add(Projections.groupProperty("current_state"));
projectionList.add(Projections.rowCount());

criteriaPurchaseRequest.setProjection(projectionList);

List results = criteriaPurchaseRequest.list();

To obtain the results:

List results = criteriaPurchaseRequest.list();
Map currentStateMap = new HashMap();
Iterator it=results.iterator();
while (it.hasNext()){
Object obj[]=(Object[])it.next();           
     CurrentState currentState = (CurrentState )obj[0];
    currentStateMap .put(currentState.getDescription().toLowerCase(), (Integer)obj[1]);
}

where CurrentState is an object that represents the column current_state (remember, Hibernate is working with objects).