IT公司面试手册

1 个或多个属性查询:
 Query query=session.createQuery(”select customername,customerid from Customer”)
 List l=query.list();
 For(int i=0;i<l.size();i++)
{
 Obejct[] object=(Object[])l.get(i);
 Object[0]  object[1]
}
}
分组: “select count(*),productname from Product group by productname order by productname”
取值与属性一样
配置的查询,在*.hbm.xml中
 <query name=”sql”>
    <![CDATA[
     from Product where productid=:productid
    ]]>
</query>
 Query query=session.getNamedQuery(sql);
联接1
 ”from Customer as customer join fetch customer.buySet”：将多的放到buySet属性中，得出的结是Customer有一个，Buy有多个
联接2
“from Customer as customer join customer.buySet”:得出的对象,customer与buy是1对1
子查询:
 ”from Customer as customer where (select count(*) from customer.buySet)>1″