HQL查詢

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普通查詢 Card爲類名，不是表名，可以寫全路徑
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());
}
}


// 條件查詢 where
public static void where() {
String hql = "from Card where cardName='三國無雙'";
Query query = son.createQuery(hql);
List<Card> cardss = query.list();
for (Card c : cardss) {
System.out.println(c.getCardName());
System.out.println(c.getCreateDate());
}
}


// 模糊查詢 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());
}
}


// 邏輯條件查詢 >
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());
}
}


// 邏輯條件查詢 between and 此處用了別名，省略了as關鍵字
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());
}
}


// 邏輯多條件查詢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刪除
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 + "行被刪除。。。");
}


// 單個屬性查詢
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);
}
}


// 多個屬性查詢 其中cardTypeName直接通過card對象的cardType對象獲得，省去了使用普通的sql語句必須多表連接查詢的麻煩
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]);
}
}


// 多個屬性查詢 面向對象方式
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());
}
}


// 函數查詢
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("總記錄數：" + o[0] + "\t最新日期爲：" + 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());
}
}


// 分組
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());
}
}


// 單個對象查詢 呵呵，奇怪吧，對象可以查詢出來
public static void simpleObject() {
String hql = "select c.cardType from  Card as c";
Query query = son.createQuery(hql);
query.setMaxResults(1);// 必須在查詢之前指定，使其返回單個對象
CardType cardType1 = (CardType) query.uniqueResult();
System.out.println(cardType1.getCardTypeName() + "\t"
+ cardType1.getCreateDate());
}


// 按照命令行參數 格式爲： :參數名
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);// 必須在查詢之前指定，使其返回單個對象
CardType cardType = (CardType) query.uniqueResult();
System.out.println(cardType.getCardTypeName() + "\t"
+ cardType.getCreateDate());
}


// 按照參數位置 從0開始
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);// 必須在查詢之前指定，使其返回單個對象
CardType cardType = (CardType) query.uniqueResult();
System.out.println(cardType.getCardTypeName() + "\t"
+ cardType.getCreateDate());
}


// 多個參數
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 查詢結果爲多個對象的集合
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 查詢結果爲多個對象的集合
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) {
// 由於保存卡片時在多的一方card進行操作，使用了級聯。但手動插入的cardType可能沒有相應的卡片
if (o[1] != null) {// 當卡片不爲空時
System.out.println(((CardType) o[0]).getCardTypeName() + "\t"
+ ((Card) o[1]).getCardName());
} else {
System.out.println(((CardType) o[0]).getCardTypeName()
+ "\t沒有相應的卡片");
}
}
}


// rightJoin 查詢結果爲多個對象的集合
public static void rightJoin() {
String hql = "from  CardType as c right join c.cards";
Query query = son.createQuery(hql);
List<Object[]> cards = query.list();
// 插入時保證了每張卡片的類型，所以此處不用判斷卡片類型是否爲空
for (Object[] o : cards) {
System.out.println(((CardType) o[0]).getCardTypeName() + "\t"
+ ((Card) o[1]).getCardName());
}
}


// 使用子查詢
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) {
// 測試方法
Transaction tr = son.beginTransaction();


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

}

hibernate投影查詢：

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;
 }

    ......省略了屬性的get,set方法

}