关于关联关系的配置,用注解配置如下(这里引用的jar包是javax.persistence)
// @ManyToOne(fetch=FetchType.LAZY)
@ManyToOne(fetch=FetchType.EAGER)
@JoinColumn(name="supplier_id",nullable=true)
private Supplier supplier;
用xml文件配置如下,这个跟注解配置有些不同,就不详解了,反正我也不会用xml配置
例子
/* 使用HQL对查询结果按照Customer的userName进行降序排序 */
public static void orderByUserNameByDesc_HQL() {
// 1.获取session对象
Session session = HibernateUtils.getSession();
// 2.编写hql语句
String hql = "from Customer c order by c.userName desc";
// 3.以HQL作为参数，调用session的createQuery()方法创建Query对象
Query query = session.createQuery(hql);
// 4.调用query对象的list()等方法遍历结果
List<Customer> list = query.list();
// 打印结果
for (Customer c : list) {
System.out.println(c.getId() + "\t" + c.getUserName());
}
}
一个使用hql来进行动态查询的使用方法(用map存储参数)
@SuppressWarnings("unchecked")public long getXXXCount(Map<String,String> conditions) throws Exception {
String hql = "select count(u.id)";
Map<String,Object> valMap = createPartHql(hql,conditions);
hql = (String)valMap.get("hql");
valMap.remove("hql");
Query query = getQueryFromMapAndHql(valMap,hql);
return (long)query.list().get(0);
}
private static Map<String,Object> createPartHql(String hql,Map<String,String> conditions){
Map<String,Object> valMap = new HashMap<>();
boolean conditionsIsNull = true;
for(Map.Entry<String, String> entry:conditions.entrySet()){
if(StringUtils.isNotEmpty(entry.getValue()))
conditionsIsNull = false;
} hql = hql+" from xxxx u where u.deleteFlg = 0";
if(StringUtils.isNotEmpty(conditions.get("roleType"))){
hql = hql+" and u.roleType = :roleType";
valMap.put("roleType", Integer.parseInt(conditions.get("roleType")));
}
if(StringUtils.isNotEmpty(conditions.get("loginId"))){
hql = hql+" and u.loginId like :loginId";
valMap.put("loginId", "%"+conditions.get("loginId")+"%");
}
valMap.put("hql", hql);
return valMap;
}
---------------------------
public Query getQueryFromMapAndHql(Map<String,Object> FieldsMap,String hql){
Query query = this.getSessionFactory().getCurrentSession().createQuery(hql);
for(Map.Entry<String, Object> entry : FieldsMap.entrySet()){
query.setParameter(entry.getKey(), entry.getValue());
}
return query;
}
public Query getQueryFromMapAndHql(Map<String,String> FieldsMap,Query query){
for(Map.Entry<String, String> entry : FieldsMap.entrySet()){
query.setParameter(entry.getKey(), entry.getValue()+"");
}
return query;
}
其他示例:
package com.qst.chapter06.demo;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.HashSet;
import java.util.List;
import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.criterion.DetachedCriteria;
import org.hibernate.criterion.Example;
import org.hibernate.criterion.MatchMode;
import org.hibernate.criterion.Restrictions;
import com.qst.chapter06.pojos.Customer;
import com.qst.chapter06.pojos.Order;
import com.qst.chapter06.pojos.Product;
import com.qst.chapter06.util.HibernateUtils;
public class HqlCriteriaBusinessDemo {
public static void main(String[] args) {
// findCustomersByAddress_HQL("青岛市");
// findCustomersByAddress_QBC("青岛市");
// orderByUserNameByDesc_HQL();
// orderByUserNameByDesc_QBC();
// 第2页，每页3条记录
// List<Customer> list=listPageCustomer_HQL(2,3);
// List<Customer> list = listPageCustomer_QBC(2, 3);
// 打印结果
// for (Customer c : list) {
// System.out.println(c.getId() + "\t" + c.getUserName());
// }
// Customer c = findOneCustomer_HQL();
// Customer c = findOneCustomer_QBC();
// System.out.println(c.getId() + "\t" + c.getUserName());
// List<Customer> list=findCustomersByName1("zhangsan1");
// List<Customer> list=findCustomersByName2("zhangsan1");
// //打印结果
// for (Customer c : list) {
// System.out.println(c.getId() + "\t" + c.getUserName());
// }
// findCustomerByJoin();
// findCustomerByFetchJoin();
// findCustomerByLeftJoin();
// findCustomerByLeftFetch();
// groupByCustomer();
// printOrders_HQL();
// printOrders_QBC();
// //////////////////////////////////////////////
// List<Product> listProduct = findProductsByHQL("打印机", 560.0);
// List<Product> listProduct = findProductsByCriteria("打印机", 560.0);
// List<Product> listProduct= findProductsByQBE(product);
// Product product=new Product();
// product.setName("打印机");
// product.setPrice(560.0);
// //////////////////////////////////////////////
// DetachedCriteria cri = DetachedCriteria.forClass(Product.class);
// // 根据用户的动态查询条件，创建DetachedCriteria对象
// cri.add(Restrictions.ilike("name", "打印机", MatchMode.ANYWHERE));
// cri.add(Restrictions.eq("price", 560.0));
// List<Product> listProduct = findProducts(cri);
// for (Product p : listProduct) {
// System.out.println(p.getId() + "\t" + p.getName() + "\t"
// + p.getPrice() + "\t" + p.getDescription());
// }
/////////////////////////////////////////////////////////////
findProductsBySubQuerys();
}
/* 使用HQL检索根据地址查询Customer */
public static void findCustomersByAddress_HQL(String address) {
// 1.获取session对象
Session session = HibernateUtils.getSession();
// 2.编写hql语句
String hql = "from Customer c where c.address = :address";
// // 3.以HQL作为参数，调用session的createQuery()方法创建Query对象
// Query query = session.createQuery(hql);
// // 4.调用Query对象的setXXX()方法为参数赋值
// query.setString("address", address);
// // 5.调用Query对象的list()等方法得到查询结果
// List<Customer> list = query.list();
// Query对象匿名方式
List<Customer> list = session.createQuery(hql)
.setString("address", address).list();
// 遍历输出结果
for (Customer c : list) {
System.out.println(c.getId() + "\t" + c.getUserName());
}
}
/* 使用QBC检索根据地址查询Customer */
public static void findCustomersByAddress_QBC(String address) {
// 1.获取session对象
Session session = HibernateUtils.getSession();
// 2.以Customer的Class对象作为参数，创建Criteria对象
Criteria critera = session.createCriteria(Customer.class);
// // 3.调用Criteria对象的add()方法，增加Criterion查询条件
// critera.add(Restrictions.eq("address", address));
// // 4.执行Criteria的list()方法返回查询结果
// List<Customer> list = critera.list();
// Criteria对象匿名方式
List<Customer> list = session.createCriteria(Customer.class)
.add(Restrictions.eq("address", address)).list();
// 遍历输出结果
for (Customer c : list) {
System.out.println(c.getId() + "\t" + c.getUserName());
}
}
/* 使用HQL对查询结果按照Customer的userName进行降序排序 */
public static void orderByUserNameByDesc_HQL() {
// 1.获取session对象
Session session = HibernateUtils.getSession();
// 2.编写hql语句
String hql = "from Customer c order by c.userName desc";
// 3.以HQL作为参数，调用session的createQuery()方法创建Query对象
Query query = session.createQuery(hql);
// 4.调用query对象的list()等方法遍历结果
List<Customer> list = query.list();
// 打印结果
for (Customer c : list) {
System.out.println(c.getId() + "\t" + c.getUserName());
}
}
/* 使用QBC检索中的Order类对查询结果按照Customer的userName进行降序排序 */
public static void orderByUserNameByDesc_QBC() {
// 1.获取session对象
Session session = HibernateUtils.getSession();
// 2.以Customer的Class对象作为参数，创建Criteria对象
Criteria critera = session.createCriteria(Customer.class);
// 3.调用criteria对象的addOrder()方法条件排序规则
critera.addOrder(org.hibernate.criterion.Order.desc("userName"));
List<Customer> list = critera.list();
// 打印结果
for (Customer c : list) {
System.out.println(c.getId() + "\t" + c.getUserName());
}
}
/* 使用HQL分页查询Customer信息 */
public static List<Customer> listPageCustomer_HQL(int pageNo, int perPageNum) {
Session session = HibernateUtils.getSession();
String hql = "from Customer c order by c.userName desc";
Query query = session.createQuery(hql);
query.setFirstResult((pageNo - 1) * perPageNum);
query.setMaxResults(perPageNum);
List<Customer> list = query.list();
return list;
}
/* 使用QBC分页查询Customer信息 */
public static List<Customer> listPageCustomer_QBC(int pageNo, int perPageNum) {
Session session = HibernateUtils.getSession();
Criteria criteria = session.createCriteria(Customer.class);
criteria.setFirstResult((pageNo - 1) * perPageNum);
criteria.setMaxResults(perPageNum);
List<Customer> list = criteria.list();
return list;
}
/* 利用HQL检索单个Customer对象 */
public static Customer findOneCustomer_HQL() {
Session session = HibernateUtils.getSession();
String hql = "from Customer c order by c.userName desc";
Customer customer = (Customer) session.createQuery(hql)
.setMaxResults(1).uniqueResult();
return customer;
}
/* 利用QBC检索单个Customer对象 */
public static Customer findOneCustomer_QBC() {
Session session = HibernateUtils.getSession();
Customer customer = (Customer) session.createCriteria(Customer.class)
.addOrder(org.hibernate.criterion.Order.desc("userName"))
.setMaxResults(1).uniqueResult();
return customer;
}
/* HQL检索3月份的订单对象 */
public static void printOrders_HQL() {
Session session = HibernateUtils.getSession();
// HQL检索日期在指定范围之内
String hql = "from Order o where o.date between ? and ?";
// 创建一个日期格式类，用于格式化日期
SimpleDateFormat dateFormat = new SimpleDateFormat(
"yyyy-MM-dd HH:mm:ss");
try {
List<Order> list = session.createQuery(hql)
.setParameter(0, dateFormat.parse("2015-03-01 00:00:00"))
.setParameter(1, dateFormat.parse("2015-03-31 23:59:59"))
.list();
// 打印结果
for (Order o : list) {
System.out.println(o.getId() + "\t" + o.getDate());
}
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/* QBC检索3月份的订单对象 */
public static void printOrders_QBC() {
Session session = HibernateUtils.getSession();
// 创建一个日期格式类，用于格式化日期
SimpleDateFormat dateFormat = new SimpleDateFormat(
"yyyy-MM-dd HH:mm:ss");
try {
// QBC检索
List<Order> list = session
.createCriteria(Order.class)
.add(Restrictions.between("date",
dateFormat.parse("2015-03-01 00:00:00"),
dateFormat.parse("2015-03-31 23:59:59"))).list();
// 打印结果
for (Order o : list) {
System.out.println(o.getId() + "\t" + o.getDate());
}
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static List<Customer> findCustomersByName1(String name) {
// 获取Session对象
Session session = HibernateUtils.getSession();
// 创建HQL
String hql = "from Customer as c where c.userName = :name";
Query query = session.createQuery(hql);
// 按照参数名字进行绑定
query.setString("name", name);
return query.list();
}
public static List<Customer> findCustomersByName2(String name) {
Session session = HibernateUtils.getSession();
String hql = "from Customer as c where c.userName = ?";
Query query = session.createQuery(hql);
// 按照参数位置进行绑定
query.setString(0, name);
return query.list();
}
/* HQL内连接 */
public static void findCustomerByJoin() {
Session session = HibernateUtils.getSession();
// 使用HQL进行内连接
String hql = "from Customer c inner join c.orders o where c.userName like :name";
Query query = session.createQuery(hql);
query.setString("name", "z%");
List<Object[]> list = query.list();
for (Object[] objs : list) {
Customer customer = (Customer) objs[0];
System.out.print(customer.getId() + " * " + customer.getUserName()
+ " * ");
Order order = (Order) objs[1];
System.out.print(order.getOrderNo() + " * ");
System.out.print(order.getDate());
System.out.println();
}
}
/* HQL预先抓取内连接 */
public static void findCustomerByFetchJoin() {
Session session = HibernateUtils.getSession();
String hql = "from Customer c inner join fetch c.orders o where c.userName like :name";
Query query = session.createQuery(hql);
query.setString("name", "z%");
List<Customer> list = query.list();
// 使用HashSet过滤重复元素
HashSet<Customer> set = new HashSet<Customer>(list);
for (Customer customer : set) {
System.out.print(customer.getId() + " " + customer.getUserName()
+ " ");
for (Order order : customer.getOrders()) {
System.out.print(order.getOrderNo() + " ");
}
System.out.println();
}
}
/* HQL左外连接 */
public static void findCustomerByLeftJoin() {
Session session = HibernateUtils.getSession();
String hql = "from Customer c left outer join c.orders o where c.address = ?";
Query query = session.createQuery(hql);
query.setString(0, "青岛市");
List<Object[]> list = query.list();
for (Object[] objs : list) {
Customer customer = (Customer) objs[0];
System.out.print(customer.getId() + " " + customer.getUserName()
+ " ");
Order order = (Order) objs[1];
if (objs[1] != null)
System.out.print(order.getOrderNo());
System.out.println();
}
}
/* 预先抓取左外连接 */
public static void findCustomerByLeftFetch() {
Session session = HibernateUtils.getSession();
String hql = "from Customer c left join fetch c.orders where c.address = ?";
Query query = session.createQuery(hql);
query.setString(0, "青岛市");
List<Customer> list = query.list();
HashSet<Customer> set = new HashSet<Customer>(list);
for (Customer customer : set) {
System.out.print(customer.getId() + " " + customer.getUserName()
+ " ");
for (Order order : customer.getOrders()) {
System.out.print(order.getOrderNo() + " ");
}
System.out.println();
}
}
public static void groupByCustomer() {
Session session = HibernateUtils.getSession();
String hql = "select c.userName,count(o) from Customer c left join c.orders o group by c.id";
Query query = session.createQuery(hql);
List<Object[]> list = query.list();
for (Object[] objs : list) {
String username = (String) objs[0];
Long count = (Long) objs[1];
System.out.println("用户名: " + username + " 订单数：" + count);
}
}
public static List<Product> findProductsByHQL(String name, Double price) {
Session session = HibernateUtils.getSession();
StringBuffer buffer = new StringBuffer();
// 生成基础SQL
buffer.append("from Product p where 1=1");
// 如果name满足条件，则加入语句中
if (name != null) {
buffer.append(" and lower(p.name) like :name");
}
// 如果age满足条件，则加入语句中
if (price != null && price != 0) {
buffer.append(" and p.price = :price");
}
Query query = session.createQuery(buffer.toString());
if (name != null) {
query.setString("name", "%" + name.toLowerCase() + "%");
}
if (price != null && price != 0) {
query.setDouble("price", price);
}
return query.list();
}
public static List<Product> findProductsByCriteria(String name, Double price) {
Session session = HibernateUtils.getSession();
Criteria criteria = session.createCriteria(Product.class);
if (name != null) {
criteria.add(Restrictions.ilike("name", name, MatchMode.ANYWHERE));
}
if (price != null && price != 0) {
criteria.add(Restrictions.eq("price", price));
}
return criteria.list();
}
public static List<Product> findProductsByQBE(Product product) {
Session session = HibernateUtils.getSession();
/* customer为样本对象，根据查询条件创建的对象 */
Example example = Example.create(product)// 根据样本对象创建Example对象
.enableLike(MatchMode.ANYWHERE)// 对所有String类型的字段进行模糊匹配
.excludeNone()// 不把为空的字段加入where子句中
.excludeZeroes()// 不把值为0的字段加入where子句中
.ignoreCase();// 忽略所有String类型字段的大小写
Criteria criteria = session.createCriteria(Product.class);
criteria.add(example);
return criteria.list();
}
// 在业务逻辑层 把DetachedCriteria对象与Session对象绑定，并返回查询结果
public static List<Product> findProducts(DetachedCriteria detachedCriteria) {
Session session = HibernateUtils.getSession();
Criteria criteria = detachedCriteria.getExecutableCriteria(session);
return criteria.list();
}
public static void findProductsBySubQuerys() {
Session session = HibernateUtils.getSession();
String hql = "from Product p where p.price=(select p1.price from Product p1 where p1.name=:name) and p.name!=:name";
Query query = session.createQuery(hql);
query.setString("name", "打印机");
List<Product> list = query.list();
for (Product p : list) {
System.out.println(p.getId() + "\t" + p.getName() + "\t"
+ p.getPrice() + "\t" + p.getDescription());
}
}
}
增加查询条件的方法如下
.add(Restrictions.eq("address", address))
/* 使用QBC检索中的Order类对查询结果按照Customer的userName进行降序排序 */
public static void orderByUserNameByDesc_QBC() {
// 1.获取session对象
Session session = HibernateUtils.getSession();
// 2.以Customer的Class对象作为参数，创建Criteria对象
Criteria critera = session.createCriteria(Customer.class);
// 3.调用criteria对象的addOrder()方法条件排序规则
critera.addOrder(org.hibernate.criterion.Order.desc("userName"));
List<Customer> list = critera.list();
// 打印结果
for (Customer c : list) {
System.out.println(c.getId() + "\t" + c.getUserName());
}
}
/* 使用QBC检索根据地址查询Customer */
public static void findCustomersByAddress_QBC(String address) {
// 1.获取session对象
Session session = HibernateUtils.getSession();
// 2.以Customer的Class对象作为参数，创建Criteria对象
Criteria critera = session.createCriteria(Customer.class);
// // 3.调用Criteria对象的add()方法，增加Criterion查询条件
// critera.add(Restrictions.eq("address", address));
// // 4.执行Criteria的list()方法返回查询结果
// List<Customer> list = critera.list();
// Criteria对象匿名方式
List<Customer> list = session.createCriteria(Customer.class)
.add(Restrictions.eq("address", address)).list();
// 遍历输出结果
for (Customer c : list) {
System.out.println(c.getId() + "\t" + c.getUserName());
}
}
时间： 2024-12-31 12:19:06