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!

+++++++++++++++++++++++++++++++++++++++++++++++++

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:

Listlist=getHibernateTemplate().find("selectnewmap(t1.c1,t2.c3)fromtable1t1,table2t2wheret1.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

Stringhql="selects.name,p.name,p.pricefromProductpinnerjoinp.supplierass";

Queryquery=session.createQuery(hql);

Listresults=query.list();

//HQL-Delete

Stringhql="deletefromProductwherename=:name";

Queryquery=session.createQuery(hql);

query.setString("name","Product1");

introwCount=query.executeUpdate();

//HQL-Function

Stringhql="selectmin(product.price),max(product.price)fromProductproduct";

Queryquery=session.createQuery(hql);

Listresults=query.list();

//HQL-FetchAssociationsHQLInnerJoin

Stringhql="fromSuppliersinnerjoinfetchs.productsasp";

Queryquery=session.createQuery(hql);

Listresults=query.list();

//HQL-NamedParameters

Stringhql="fromProductwhereprice>:price";

Queryquery=session.createQuery(hql);

query.setDouble("price",2.0);

Listresults=query.list();

Stringhql="fromProductasproductwhereproduct.supplier=:supplier";

Queryquery=session.createQuery(hql);

query.setEntity("supplier",supplier);

Listresults=query.list();

//HQL-Update

Stringhql="updateSuppliersetname=:newNamewherename=:name";

Queryquery=session.createQuery(hql);

query.setString("name","SupplierName1");

query.setString("newName","s1");

introwCount=query.executeUpdate();

//HQL-where

Stringhql="fromProductwhereprice>2.0andnamelike'P%'";

Queryquery=session.createQuery(hql);

Listresults=query.list();

//HQL-Map

Stringhql="selectnewmap(usr.nameasuserName,usr.passwordaspassword)fromUserusr";

Queryquery=session.createQuery(hql);

Listlist=query.list();

Mapgoods=(Map)list.get(0);

【注】

Stringhql="selectnewmap(usr.nameasuserName,usr.passwordaspassword) fromcom.jason.Userusr";

Stringhql="selectnewmap(usr.nameasuserName,usr.passwordaspassword)fromcom.jason.Userusr";

由于from之前的空格,引起unexpectedtoken: from

//selectnew

给一个构建函数:

publicclassDepartment(Departmentd,IntegeremployeeSize)

然后写成这样:

SELECTnewDepartment(department,count(employee.id))FROM.....

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

相关推荐