怎样用hibernate的hql查询查询成map或list

HQL原来还可以这么用呀,呵呵,长见识了!
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这里制作一个引子,具体内容比较多,而且hibernate文档里的hql篇写的很详细
可以这么用:
List list = getHibernateTemplate().find("select new map(t1.c1,t2.c3) from table1 t1 ,table2 t2 where t1.c1=t2.c2");
这样的话list里的每个元素都是一个map,每个map里包含两个元素
注意:这里的table1和table2都是class名并不是真的表名,毕竟这是hql。除了可以用map还还支持list和自定义的bean。


//HQL-Associations
String hql = "select s.name, p.name, p.price from Product p inner join p.supplier as s";
Query query = session.createQuery(hql);
List results = query.list();


//HQL-Delete
String hql = "delete from Product where name = :name";
Query query = session.createQuery(hql);
query.setString("name","Product 1");
int rowCount = query.executeUpdate();


//HQL-Function
String hql = "select min(product.price), max(product.price) from Product product";
Query query = session.createQuery(hql);
List results = query.list();


//HQL-Fetch Associations HQL Inner Join
String hql = "from Supplier s inner join fetch s.products as p";
Query query = session.createQuery(hql);
List results = query.list();


//HQL-Named Parameters
String hql = "from Product where price > :price";
Query query = session.createQuery(hql);
query.setDouble("price",2.0);
List results = query.list();
String hql = "from Product as product where product.supplier=:supplier";
Query query = session.createQuery(hql);
query.setEntity("supplier",supplier);
List results = query.list();


//HQL-Update
String hql = "update Supplier set name = :newName where name = :name";
Query query = session.createQuery(hql);
query.setString("name","Supplier Name 1");
query.setString("newName","s1");
int rowCount = query.executeUpdate();


//HQL-where
String hql = "from Product where price > 2.0 and name like 'P%'";
Query query = session.createQuery(hql);
List results = query.list();

//HQL-Map
String hql = " select new map(usr.name as userName, usr.password as password) from User usr";
Query query = session.createQuery(hql);
List list = query.list();
Map goods =(Map)list.get(0);

【注】
    String hql = " select new map(usr.name as userName, usr.password as password)  from com.jason.User usr";
    String hql = " select new map(usr.name as userName, usr.password as password) from com.jason.User usr";
由于from之前的空格,引起unexpected token:  from



//select new

给一个构建函数:
public class Department(Department d, Integer employeeSize)

然后写成这样:
SELECT new Department(department, count(employee.id)) FROM .....

本文转自vtrtbb.spaces.live.com/blog/cns!14B0BD73BAB3D6CD!192.entry

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