使用预测

如果我们只想检索几列，我们可以使用 Projections 类来执行此操作。例如，以下代码检索标题列

 // Selecting all title columns
  List review = session.createCriteria(TravelReview.class)
        .setProjection(Projections.property("title"))
    .list();
  // Getting row count
  review = session.createCriteria(TravelReview.class)
    .setProjection(Projections.rowCount())
    .list();
  // Fetching number of titles
  review = session.createCriteria(TravelReview.class)
    .setProjection(Projections.count("title"))
    .list();