Hibernate中使用离线条件查询

Hibernate提供了Criteria对象，用户动态加入查询条件，使在跟根据指定查询条件查询更加灵活。

package cn.itcast.shop.product.dao;

import java.util.List;

import org.hibernate.criterion.DetachedCriteria;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Restrictions;
import org.springframework.orm.hibernate4.support.HibernateDaoSupport;

import cn.itcast.shop.product.vo.Product;
import cn.itcast.shop.user.utils.PageHibernateCallback;

/**
 * 商品DAO 类
 * 
 * @author Charlotte
 *
 */
public class ProductDao extends HibernateDaoSupport {
	// 首页上热门商品查询
	public List findHot() {
		// 使用离线条件查询.
		DetachedCriteria criteria = DetachedCriteria.forClass(Product.class);
		// 查询热门的商品，条件就是 is_hot = 1
		criteria.add(Restrictions.eq("is_hot", 1));
		// 倒叙排序进行输出
		criteria.addOrder(Order.desc("pdate"));
		// 执行查询
		List list = (List) this.getHibernateTemplate().findByCriteria(criteria, 0, 10);
		return list;
	}

	// 首页上最新商品的查询
	public List findNew() {
		// 使用离线查询
		DetachedCriteria criteria = DetachedCriteria.forClass(Product.class);
		// 按日期进行倒叙查询
		criteria.addOrder(Order.desc("pdate"));
		// 执行查询
		List list = (List) this.getHibernateTemplate().findByCriteria(criteria, 0, 10);
		return list;
	}

	// 根据 ID 查询商品
	public Product findByPid(Integer pid) {
		return this.getHibernateTemplate().get(Product.class, pid);
	}

	// 根据商品分类 id 查询商品的个数
	public int findCountCid(Integer cid) {
		String hql = "select count(*) from Product p where p.categorySecond.category.cid = ? ";
		List list = (List) this.getHibernateTemplate().find(hql, cid);
		if (list != null && list.size() > 0) {
			return list.get(0).intValue();
		}
		return 0;
	}

	// 根据分类 id 查询商品的集合
	public List findByPageCid(Integer cid, int begin, int limit) {
		String hql = "select p from Product p join p.categorySecond cs join cs.category c where c.cid = ?";
		// 分页另一种写法
		List list = this.getHibernateTemplate()
				.execute(new PageHibernateCallback(hql, new Object[] { cid }, begin, limit));
		if (list != null && list.size() > 0) {
			return list;
		}
		return null;
	}

	// 根据二级分类查询商品个数
	public int findCountCsid(Integer csid) {
		String hql = "select count(*) from Product p where p.categorySecond.csid = ?";
		List list = (List) this.getHibernateTemplate().find(hql, csid);
		return list.get(0).intValue();
	}

	// 根据二级分类查询商品
	public List findByPageCsid(Integer csid, int begin, int limit) {
		String hql = "select p from Product p join p.categorySecond cs where cs.csid = ?";
		List list = this.getHibernateTemplate()
				.execute(new PageHibernateCallback(hql, new Object[] { csid }, begin, limit));
		if (list != null && list.size() > 0) {
			return list;
		}
		return null;
	}

}