/**
* * 分页的查询数据列表
*
* @param firstResult从结果列表中的哪个索引开始取数据
* @param maxResults 最多取多少条数据
* @return 一页的数据列表 + 总记录数
*/
@SuppressWarnings("unchecked")
public QueryResult findAll(int firstResult, int maxResults) {
Session session = HibernateUtil.currentSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
// 方式二：方法链
List<Upload> list =
session
.createQuery("FROM Upload")
.setFirstResult(firstResult)
.setMaxResults(maxResults)
.list();
// 查询总记录数
Long count = (Long) session.createQuery("SELECT COUNT(*) FROM Upload").uniqueResult();
tx.commit();
// 返回结果
return new QueryResult(count.intValue(), list);
} catch (RuntimeException e) {
tx.rollback();
throw e;
} finally {
HibernateUtil.closeSession();
}
}
// 保存
public void save(Upload upload) {
Session session = HibernateUtil.currentSession();
try {
Transaction tx = session.beginTransaction(); // 开始事务
session.save(upload);
tx.commit(); // 提交事务
} catch (RuntimeException e) {
session.getTransaction().rollback(); // 回滚事务
throw e;
} finally {
HibernateUtil.closeSession(); // 关闭Session
}
}
// 更新
public void update(Upload upload) {
Session session = HibernateUtil.currentSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
session.update(upload); // 操作
tx.commit();
} catch (RuntimeException e) {
tx.rollback();
throw e;
} finally {
HibernateUtil.closeSession();
}
}
// 查询
public Upload getById(int id) {
Session session = HibernateUtil.currentSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
Upload upload = (Upload) session.get(Upload.class, id); // 操作
tx.commit();
return upload;
} catch (RuntimeException e) {
tx.rollback();
throw e;
} finally {
HibernateUtil.closeSession();
}
}
// 删除
public void deleteById(int id) {
Session session = HibernateUtil.currentSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
Object upload = session.get(Upload.class, id); // 要先获取到这个对象
session.delete(upload); // 删除的是实体对象
tx.commit();
} catch (RuntimeException e) {
tx.rollback();
throw e;
} finally {
HibernateUtil.closeSession();
}
}
public static void updateProduct(Products pro) {
Transaction trns = null;
Session session = HibernateUtil.getSessionFactory().openSession();
try {
trns = session.beginTransaction();
//
Products lolo = new Products();
lolo.setId(pro.getId());
lolo.setName(pro.getName());
lolo.setAvalibleAmmount(pro.getAvalibleAmmount());
lolo.setUnit(pro.getUnit());
lolo.setDescription(pro.getDescription());
//
session.saveOrUpdate(lolo);
session.getTransaction().commit();
} catch (RuntimeException e) {
if (trns != null) {
trns.rollback();
}
e.printStackTrace();
} finally {
session.flush();
session.close();
}
}
// 查询所有
public List<Upload> findAll() {
Session session = HibernateUtil.currentSession();
Transaction tx = null;
try {
tx = session.beginTransaction();
// 方式二：使用Criteria查询
Criteria criteria = session.createCriteria(Upload.class);
List<Upload> list = criteria.list();
tx.commit();
return list;
} catch (RuntimeException e) {
tx.rollback();
throw e;
} finally {
HibernateUtil.closeSession();
}
}
public static void main(String[] args) {
SessionFactory sessionFactory = HibernateUtil.getSessionFactroy();
// We can obtain a sessionFactroy using openSession()
Session session = sessionFactory.openSession();
// Using Aggregate functions in Criteria
Criteria criteria = session.createCriteria(Product.class);
ProjectionList projectionList = Projections.projectionList();
projectionList.add(Projections.max("price"));
criteria.setProjection(projectionList);
float maxPrice = (float) criteria.uniqueResult();
System.out.println("Max Price:" + maxPrice);
/*
//Partial Records are called Projections
//Fetch only Product name and price
Criteria criteria=session.createCriteria(Product.class);
Criterion criterion =Restrictions.gt("id", 3);
Criterion criterion2 = Restrictions.like("name","G%" );
LogicalExpression logicalExpression= Restrictions.and(criterion,criterion2);
criteria.add(logicalExpression);
//using projectionlist() in Projection,we can filter the records in Criteria
ProjectionList projectionList = Projections.projectionList();
projectionList.add(Projections.property("name"));
projectionList.add(Projections.property("price"));
criteria.setProjection(projectionList);
List<Object[]> objectArrayList = criteria.list();
for (Object[] objects : objectArrayList) {
System.out.println("Product Name :"+objects[0]);
System.out.println("Product price :"+objects[1]);
}*/
/* //Using methods we create Queries using Criteria
Criteria criteria=session.createCriteria(Product.class);
//Criterians are the conditions used for the record
Criterion criterion =Restrictions.gt("id", 3);
Criterion criterion2 = Restrictions.like("name","G%" );
// criteria.add(criterion);
// criteria.add(criterion2);
//It returns a object called as Logical Expression
//using Restrictions.or() ,we get all records which satisfy anyone conditions
//using Restrictions.and() ,we get all records which satisfy all conditions
LogicalExpression logicalExpression= Restrictions.and(criterion,criterion2);
criteria.add(logicalExpression);
List<Product> productList = criteria.list();
for (Product product : productList) {
System.out.println("Id :"+product.getId());
System.out.println("Name :"+product.getName());
System.out.println("Description :"+product.getDescription());
System.out.println("Price :"+product.getPrice());
System.out.println();
}
*/
/*//using Joins(inner-Join)
//Query query = session.createQuery("SELECT p,s FROM Product p inner join p.supplier s");
//using Joins(left-Outer-Join)
Query query = session.createQuery("SELECT p,s FROM Product p left outer join p.supplier s");
List<Object[]> lisfOfArrays=query.list();
for (Object[] objects : lisfOfArrays) {
Product product = (Product) objects[0];
Supplier supplier = (Supplier) objects[1];
System.out.println("Id :"+product.getId());
System.out.println("Name :"+product.getName());
System.out.println("Description :"+product.getDescription());
System.out.println("Price :"+product.getPrice());
System.out.println();
System.out.println("Supplier Id :"+supplier.getId());
System.out.println("Supplier Name :"+supplier.getName());
System.out.println();
System.out.println();
}
*/
// //Using Aggrigate Functions---AVG,MIN etc
//
//
// Query query =session.createQuery("select max(b.bidAmount) from Bid b");
//
// float maxPrice = (float) query.uniqueResult();
//
// System.out.println("Maximim Price is::"+maxPrice);
/* //If we want only two rows of the table
//This type of queries are called Projections
Query query =session.createQuery("select c.name,c.countrycode from City c where c.id> :cid and c.name like :cname");
query.setInteger("cid", 4079);
query.setString("cname", "L%");
List<Object[]> objectArrayList = query.list();
for (Object[] objects : objectArrayList) {
System.out.println("Name :"+objects[0]);
System.out.println("CountryCode :"+objects[1]);
System.out.println();
}*/
/*// HQL Query
//All city Records from City Table Using City class
//Method -1
//Query query =session.createQuery("from City");
//method-2(c refers to City class type)(Best-Way)
//It is hard-coded with values
//Query query =session.createQuery("select c from City c where c.id>4079 and c.name like 'L%'");
//Reusable Query (using Positional Binding parameters)
//0 //1
//Query query =session.createQuery("select c from City c where c.id> ? and c.name like ?");
//query.setInteger(0, 4079);
//query.setString(1, "L%");
//Reusable Query (using named Binding parameters)
//cid and cname are Named Bind Parameters
Query query =session.createQuery("select c from City c where c.id> :cid and c.name like :cname");
query.setInteger("cid", 4079);
query.setString("cname", "L%");
//It will list all records of city table
List<City> city = query.list();
for (City cities : city) {
//System.out.println("ID :"+cities.getId());
System.out.println("Name :"+cities.getName());
System.out.println("CountryCode:"+cities.getCountrycode());
//System.out.println("District :"+cities.getDistrict());
//System.out.println("Population :"+cities.getPopulation());
System.out.println();
}*/
/*//Many To many Relation(Item-Category)
Item item = (Item) session.get(Item.class, 108);
System.out.println("Item ID:" + item.getId());
System.out.println("Item Name:" + item.getName());
Set<Category> categories = item.getCategories();
for (Category category : categories) {
System.out.println("Category ID:" +category.getId());
System.out.println("Category Name:" +category.getName());
System.out.println();
}*/
// Item item = (Item) session.get(Item.class, 101);
//
// System.out.println("Item ID:" + item.getId());
// System.out.println("Item Name" + item.getName());
//
// // Getting Associated Bid Records with the ID
//
// Set<Bid> bids = item.getBids();
//
// for (Bid bid : bids) {
//
// System.out.println("BidId :"+bid.getId());
// System.out.println("Bid Amount:"+bid.getBidAmount());
// System.out.println();
// }
/*
* //Add a City Record City city = new
* City(4080,"London","UK","LDN",435678);
*
* //We need a Transaction to use Insert,Update Delete Transaction
* transaction = session.getTransaction(); transaction.begin();
*
* session.save(city);
*
* transaction.commit();
*
* session.close();
*/
// //getting record by ID
// City city =(City)session.get(City.class, 102);
//
// System.out.println("ID :"+city.getId());
// System.out.println("Name :"+city.getName());
// System.out.println("CountryCode:"+city.getCountrycode());
// System.out.println("District :"+city.getDistrict());
// System.out.println("Population :"+city.getPopulation());
}