title: org.hibernate.hql.ast.QuerySyntaxException with Hibernate
body: <p>I'm new to using Hibernate with Java. I'm getting the following exception. The stuff that I found online regarding this error didn't seem to help. Any ideas?  The Exception:</p>
  
  <pre><code>java.lang.IllegalArgumentException: org.hibernate.hql.ast.QuerySyntaxException: 
  
  ApplPerfStats is not mapped [select count(c) from ApplPerfStats c]
      at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:601)
      at org.hibernate.ejb.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:96)
      at com.icesoft.icefaces.samples.datatable.jpa.CustomerDAO.findTotalNumberCustomers(CustomerDAO.java:89)
      at com.icesoft.icefaces.samples.datatable.ui.SessionBean.getDataPage(SessionBean.java:189)
      at com.icesoft.icefaces.samples.datatable.ui.SessionBean.access$0(SessionBean.java:185)
      at com.icesoft.icefaces.samples.datatable.ui.SessionBean$LocalDataModel.fetchPage(SessionBean.java:245)
      at com.icesoft.icefaces.samples.datatable.ui.PagedListDataModel.getPage(PagedListDataModel.java:121)
      at com.icesoft.icefaces.samples.datatable.ui.PagedListDataModel.getRowCount(PagedListDataModel.java:100)
      at com.icesoft.faces.component.datapaginator.DataPaginator.isModelResultSet(DataPaginator.java:1091)
      at com.icesoft.faces.component.datapaginator.DataPaginatorRenderer.encodeBegin(DataPaginatorRenderer.java:201)
  </code></pre>
  
  <p>The place where this is called:</p>
  
  <pre><code>@SuppressWarnings("unchecked")
  public Long findTotalNumberCustomers() {
      EntityManagerHelper.log("finding number of Customer instances", Level.INFO, null);
      try {
          String queryString = "select count(c) from ApplPerfStats c";
          return (Long) getEntityManager().createQuery(queryString).getSingleResult();
      } catch (RuntimeException re) {
          EntityManagerHelper.log("find number of Appl_perf_stats failed",
                  Level.SEVERE, re);
          throw re;
      }
  }
  </code></pre>
  
  <p>The class that maps to the database table:</p>
  
  <pre><code>package com.icesoft.icefaces.samples.datatable.jpa;
  
  import java.sql.Timestamp;
  
  import javax.persistence.Column;
  import javax.persistence.Entity;
  import javax.persistence.Id;
  import javax.persistence.Table;
  
  @Entity
  @Table(name = "Appl_perf_stats", uniqueConstraints = {})
  public class ApplPerfStats implements java.io.Serializable {
  .....
  </code></pre>
  
  <p>Thanks,</p>
  
  <p>Tam</p>