hibernate

Posted 2020-09-16 祥福有梦想

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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();
}
}

[java] view plain copy

print ?

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

}

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