hibernate

package com.tudou.hibernates.t1;

import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

public class TestGetHql {
    private static Configuration cfg = new Configuration().configure();
    private static SessionFactory fac = cfg.buildSessionFactory();
    private static Session son = fac.openSession();

    // hql普通查询 Card为类名，不是表名，可以写全路径
    public static void from() {
        String hql = "from Card";
        Query query = son.createQuery(hql);
        List<Card> cards = query.list();
        for (Card c : cards) {
            System.out.println(c.getCardName());
            System.out.println(c.getCreateDate());
        }
    }

    // 条件查询 where
    public static void where() {
        String hql = "from Card where cardName='三国无双'";
        Query query = son.createQuery(hql);
        List<Card> cardss = query.list();
        for (Card c : cardss) {
            System.out.println(c.getCardName());
            System.out.println(c.getCreateDate());
        }
    }

    // 模糊查询 like
    public static void like() {
        String hql = "from Card where cardName like '%世%'";
        Query query = son.createQuery(hql);
        List<Card> cards = query.list();
        for (Card c : cards) {
            System.out.println(c.getCardName());
            System.out.println(c.getCreateDate());
        }
    }

    // 逻辑条件查询 >
    public static void gt() {
        String hql = "from Card c where c.createDate >'2011-08-08'";
        Query query = son.createQuery(hql);
        List<Card> cards = query.list();
        for (Card c : cards) {
            System.out.println(c.getCardName());
            System.out.println(c.getCreateDate());
        }
    }

    // 逻辑条件查询 between and 此处用了别名，省略了as关键字
    public static void between() {
        String hql = "from Card c where c.createDate between '2011-08-08' and '2022-11-11'";
        Query query = son.createQuery(hql);
        List<Card> cards = query.list();
        for (Card c : cards) {
            System.out.println(c.getCardName());
            System.out.println(c.getCreateDate());
        }
    }

    // 逻辑多条件查询and
    public static void and() {
        String hql = "from Card c where c.createDate between '2011-01-08' and '2022-11-11' and c.cardName like '%世%'";
        Query query = son.createQuery(hql);
        List<Card> cards = query.list();
        for (Card c : cards) {
            System.out.println(c.getCardName());
            System.out.println(c.getCreateDate());
        }
    }

    // update 更新
    public static void update() {
        String hql = "update Card as c set c.createDate='2011-03-03' where c.cardType.cardTypeId=3";
        Query query = son.createQuery(hql);
        int num = query.executeUpdate();
        System.out.println(num + "行被更新。。。");
    }

    // delete删除
    public static void delete() {
        String hql = "delete from  Card as c where c.createDate='2011-03-04'";
        Query query = son.createQuery(hql);
        int num = query.executeUpdate();
        System.out.println(num + "行被删除。。。");
    }

    // 单个属性查询
    public static void simpleProperty() {
        String hql = "select c.cardName from  Card as c where c.cardType.cardTypeId=1";
        Query query = son.createQuery(hql);
        List<String> name = query.list();
        for (String s : name) {
            System.out.println(s);
        }
    }

    // 多个属性查询 其中cardTypeName直接通过card对象的cardType对象获得，省去了使用普通的sql语句必须多表连接查询的麻烦
    public static void mulProperty() {
        String hql = "select c.cardName,c.cardType.cardTypeName,c.createDate from  Card as c where c.cardType.cardTypeId=1";
        Query query = son.createQuery(hql);
        List<Object[]> obj = query.list();
        for (Object[] o : obj) {
            System.out.println(o[0] + "\t" + o[1] + "\t" + o[2]);
        }
    }

    // 多个属性查询 面向对象方式
    public static void orientedObject() {
        String hql = "select new Card(c.cardName,c.createDate) from  Card as c";
        Query query = son.createQuery(hql);
        List<Card> cards = query.list();
        for (Card c : cards) {
            System.out.println(c.getCardName() + "\t" + c.getCreateDate());
        }
    }

    // 函数查询
    public static void function() {
        String hql = "select count(*),max(c.createDate) from  Card as c";
        Query query = son.createQuery(hql);
        List<Object[]> oo = query.list();
        for (Object[] o : oo) {
            System.out.println("总记录数：" + o[0] + "\t最新日期为：" + o[1]);
        }
    }

    // 排序
    public static void orderBy() {
        String hql = "from  Card as c order by c.createDate desc";
        Query query = son.createQuery(hql);
        List<Card> cards = query.list();
        for (Card c : cards) {
            System.out.println(c.getCardName() + "\t" + c.getCreateDate());
        }
    }

    // 分组
    public static void groupBy() {
        String hql = "from  Card as c group by c.cardType.cardTypeId";
        Query query = son.createQuery(hql);
        List<Card> cards = query.list();
        for (Card c : cards) {
            System.out.println(c.getCardName() + "\t" + c.getCreateDate());
        }
    }

    // 单个对象查询 呵呵，奇怪吧，对象可以查询出来
    public static void simpleObject() {
        String hql = "select c.cardType from  Card as c";
        Query query = son.createQuery(hql);
        query.setMaxResults(1);// 必须在查询之前指定，使其返回单个对象
        CardType cardType1 = (CardType) query.uniqueResult();
        System.out.println(cardType1.getCardTypeName() + "\t"
                + cardType1.getCreateDate());
    }

    // 按照命令行参数 格式为： :参数名
    public static void parameter() {
        String hql = "select c.cardType from  Card as c where c.cardType.cardTypeId=:id";
        Query query = son.createQuery(hql);
        query.setParameter("id", 1);
        query.setMaxResults(1);// 必须在查询之前指定，使其返回单个对象
        CardType cardType = (CardType) query.uniqueResult();
        System.out.println(cardType.getCardTypeName() + "\t"
                + cardType.getCreateDate());
    }

    // 按照参数位置 从0开始
    public static void parameterPosition() {
        String hql = "select c.cardType from  Card as c where c.cardType.cardTypeId=?";
        Query query = son.createQuery(hql);
        query.setParameter(0, 1);
        query.setMaxResults(1);// 必须在查询之前指定，使其返回单个对象
        CardType cardType = (CardType) query.uniqueResult();
        System.out.println(cardType.getCardTypeName() + "\t"
                + cardType.getCreateDate());
    }

    // 多个参数
    public static void mulParameter() {
        String hql = "from  Card as c where c.cardType.cardTypeId in (3,2)";
        Query query = son.createQuery(hql);
        // query.setParameterList("id", new Object[]{1,2});
        List<Card> cards = query.list();
        for (Card o : cards) {
            System.out.println(o.getCardName());
        }
    }

    // inner join 查询结果为多个对象的集合
    public static void innerJoin() {
        String hql = "from  Card as c inner join c.cardType";
        Query query = son.createQuery(hql);
        List<Object[]> cards = query.list();
        for (Object[] o : cards) {
            System.out.println(((Card) o[0]).getCardName() + "\t"
                    + ((CardType) o[1]).getCreateDate());
        }
    }

    // leftJoin 查询结果为多个对象的集合
    public static void leftJoin() {
        String hql = "from  CardType as c left join c.cards";
        Query query = son.createQuery(hql);
        List<Object[]> cards = query.list();
        for (Object[] o : cards) {
            // 由于保存卡片时在多的一方card进行操作，使用了级联。但手动插入的cardType可能没有相应的卡片
            if (o[1] != null) {// 当卡片不为空时
                System.out.println(((CardType) o[0]).getCardTypeName() + "\t"
                        + ((Card) o[1]).getCardName());
            } else {
                System.out.println(((CardType) o[0]).getCardTypeName()
                        + "\t没有相应的卡片");
            }
        }
    }

    // rightJoin 查询结果为多个对象的集合
    public static void rightJoin() {
        String hql = "from  CardType as c right join c.cards";
        Query query = son.createQuery(hql);
        List<Object[]> cards = query.list();
        // 插入时保证了每张卡片的类型，所以此处不用判断卡片类型是否为空
        for (Object[] o : cards) {
            System.out.println(((CardType) o[0]).getCardTypeName() + "\t"
                    + ((Card) o[1]).getCardName());
        }
    }

    // 使用子查询
    public static void childSelect() {
        String hql = "from  CardType as c where (select count(*) from c.cards)>0";
        Query query = son.createQuery(hql);
        List<CardType> cards = query.list();
        for (CardType c : cards) {
            System.out.println(c.getCardTypeName() + "\t" + c.getCreateDate());
        }
    }

    // 程序入口
    public static void main(String[] args) {
        // 测试方法
        Transaction tr = son.beginTransaction();

        // update();
        mulParameter();
        tr.commit();
        son.close();
        fac.close();
    }
}

hibernate投影查询：

String hql="select u.id,u.name from user as u"  //1方法

String hql="select new com.mypack.User2(u.id,u.name) from User as u "  //2方法

Iterator userHQL= session.createQuery(hql).iterate();

 

while (userHql.hasNext()) {
   User user=(User)userHql.next();
   

   Object[] row=(Object[]) userHql.next();
   int id=(Integer)row[0];
   String nameString =(String)row[1];
   System.out.print(id+"\t"+nameString);
   
   //User2 user2=(User2) userHql.next();
   //System.out.println(user2.getId()+"\t\t"+user2.getName());
  } 

--------------------------------------------------

package com.mypack;

public class User2 {
 private int id;
 private String name;
 public User2(int id,String nameString){
  this.id=id;
  this.name=nameString;
 }

    ......省略了属性的get,set方法

}