@Test
  public void testFindSelected() throws Exception {
    createEntity(1L, "h1", "global", "version1");
    HostConfigMapping coreSiteConfigV1 = createEntity(1L, "h1", "core-site", "version1");
    HostEntity hostEntity = hostDAO.findByName("h1");
    
    Set<HostConfigMapping> targets = hostConfigMappingDAO.findSelected(1L, hostEntity.getHostId());
    Assert.assertEquals("Expected two entities", 2, targets.size());

    coreSiteConfigV1.setSelected(0);
    hostConfigMappingDAO.merge(coreSiteConfigV1);
    
    createEntity(1L, "h1", "core-site", "version2");

    targets = hostConfigMappingDAO.findSelected(1L, hostEntity.getHostId());
    Assert.assertEquals("Expected two entities", 2, targets.size());
  }
Tests host config mapping DAO and Entities
ambari-server/src/test/java/org/apache/ambari/server/orm/dao/HostConfigMappingDAOTest.java