Hibernate(五)

================================criteria（QBC）查询========================
QBC，（容器）又名对象查询：采用对象的方式（主要是criteria的实例）封装查询条件

criteria实例：SQL语句封装，以一个对象的形式展现

最大优势：动态查询

语法：
   步骤：
       1.创建criteria对象，createCriteria(Dept.class)
       2.Restrictions 条件查询
       3.添加条件实例，add
       4.获取数据表的数据，list()
   范例：
   1.查询所有的部门
       Criteria criteria = session.createCriteria(Dept.class);
       List<Dept> list = criteria.list();

Restrictions:限制结果集内容--条件查询
   常用方法：
       1.Restrictions.eq(持久化类的属性名，字段的数值 )
       2.Restrictions.in( )
       3.Restrictions.like( )
       4.Restrictions.and( )
       5.Restrictions.ilike( )       大小写不敏感
       6.Restrictions.or( )
       7.Restrictions.between( )
       8.Restrictions.gt( )
       9.Restrictions.ge( )
       10.Restrictions.lt( )
       11.Restrictions.le( )
       12.Restrictions.disjunction( )           多个条件(.add()形式的条件)
       13.Restrictions.sqlRestriction( )       多个条件(字符串形式的条件)
   范例：
   1.查询位置在"1楼"的部门
       Criteria criteria = session.createCriteria(Dept.class);
       Criterion critrion = Restrictions.eq("location", "1楼");
       criteria = criteria.add(critrion);
       List<Dept> list = criteria.list();
   2.查询年龄大于20，或者用户名中含有”马“的记录
       criteria.add(Restrictions.sqlRestriction(" age > 20 or username = '% 马 %' "));

排序：org.hibernate.criterion.Order
   语法：
       addOrder(Order.asc())
       addOrder(Order.desc())

   范例：先按工资升序排序，再按编号降序排序
       List<Emp> list = session.createCriteria(Emp.class)
           .add(Restrictions.gt("salary", 4000D))
           .addOrder(Order.asc("salary"))
           .addOrder(Order.desc("empNo")).list();

Example示例查询（QBE）：
   属性条件多，可以Example取代Restrictions。创建一个对象模板，以它为查询依据，查询出属性与之类似的对象
   范例：所有年龄等于21的用户信息


分页：
   方法：
       setFirstResult(int firstResult)
       setMaxResult(int maxResult)
   范例：查询出工资最高的两名员工
       List<Emp> list = session.createCriteria(Emp.class)
           .add(Restrictions.isNotNull("salary"))
           .addOrder(Order.desc("salary"))
           .setFirstResult(0)
           .setMaxResults(2).list();

查询唯一对象：
   方法           说明                               Query   Criteria
   list()           返回List集合                       支持   支持
   iterate()       返回Iterator迭代器，只查询出ID值。   支持   不支持
   uniqueResult()   返回唯一对象                       支持   支持

   范例：查询工资最高的员工
   Emp emp = (Emp) session.createCriteria(Emp.class)
        .add(Restrictions.isNotNull("salary"))
        .addOrder(Order.desc("salary"))
        .setMaxResults(1)
        .uniqueResult();

关联：建立内连接或迫切左外连接4
   方法：
       createCriteria()
       createAlias()

   范例：
   1.List<Emp> list = session.createCriteria(Emp.class)
        .add(Restrictions.ilike("empName", "a", MatchMode.ANYWHERE))
        .createCriteria("dept")
        .add(Restrictions.eq("deptName", "财务部").ignoreCase()) .list();
   2.List<Emp> list = session.createCriteria(Emp.class, "e")
        .createAlias("dept", "d")
        .add(Restrictions.ilike("e.empName", "a",MatchMode.ANYWHERE))
        .add(Restrictions.eq("d.deptName", "财务部").ignoreCase()).list();

投影：
   方法：
       org.hibernate.criterion.Projection接口
       org.hibernate.criterion.Projections类

   范例：
   1.List<String> list = session.createCriteria(Dept.class)
        .setProjection(Property.forName("deptName")).list();
   2.List<Object[]> list = session
        .createCriteria(Emp.class)
        .setProjection(Projections.projectionList()
                        .add(Property.forName("empName"))
                        .add(Property.forName("hiredate"))).list();

分组：投影实现分组统计功能
   方法：org.hibernate.criterion.Projections类提供了使用聚合函数查询的方法
           方法                               说明
       1.Projections.groupProperty()   分组
       2.Projections.rowCount( )       统计记录数
       3.Projections.avg()               统计平均值
       4.Projections.min()               统计最小值
       5.Projections.max()               统计最大值
       6.Projections.count()           统计某一字段的非空记录数
       7.Projections.sum()               统计某一字段的求和
       8.Projections.projectionList()   实现一次查询调用多个聚合查询方法
   范例：

==============================DetachedCriteria=============================
CriteriaSpecification-->Criteria-->DetachedCriteria

Criteria和DetachedCriteria均可使用Criteria与Projection设置条件查询。创建形式不同：
   Criteria，Session进行创建
   DetachedCriteria，创建无须Session

适用范围：
   在Web层，程序员使用DetachedCriteria构造查询条件。然后将DetachedCriteria作为方法调用参数传递给业务成对象。
   业务层对象获得DetachedCriteria后，可以在Session范围内直接构造Criteria进行查询。
   因此，查询语句的构造完全被搬离到Web层实现，而业务查询与查询条件构造完全解耦。

方法：
   createAlias()
   createCriteria()

   范例：
   1.DetachedCriteria detachedCriteria = DetachedCriteria
        .forClass(Emp.class, "e")
        .createAlias("e.dept", "d")
        .add(Restrictions.eq("d.deptName", "财务部"))
        .add(Restrictions.ilike("e.empName", "a", MatchMode.ANYWHERE));
     List<Emp> list = detachedCriteria.getExecutableCriteria(session).list();

   2.DetachedCriteria avgSalary = DetachedCriteria.forClass(Emp.class, "e")
        .setProjection(Property.forName("salary").avg());
      List<Emp> list = session.createCriteria(Emp.class)
        .add(Property.forName("salary").gt(avgSalary)).list();

======================================综合范例=======================================
1.entity包
a.Dept

 1 package com.Elastic.HibernateDemo3.ivy.entity;
 2 import java.io.Serializable;
 3 import java.util.Set;
 4 public class Dept implements Serializable {
 5     private static final long serialVersionUID = 2261199233032137882L;
 6     private Integer deptId;
 7     private String deptName;
 8     private String location;
 9     
10     //多对一：一个部门有多个员工
11     //set：唯一
12     private Set<Emp> emps;
13     
14     public Set<Emp> getEmps() {
15         return emps;
16     }
17     public void setEmps(Set<Emp> emps) {
18         this.emps = emps;
19     }
20 
21     public Integer getDeptId() {
22         return deptId;
23     }
24     public void setDeptId(Integer deptId) {
25         this.deptId = deptId;
26     }
27     public String getDeptName() {
28         return deptName;
29     }
30     public void setDeptName(String deptName) {
31         this.deptName = deptName;
32     }
33     public String getLocation() {
34         return location;
35     }
36     public void setLocation(String location) {
37         this.location = location;
38     }
39 }

b.Dept.hbm.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC
 3     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 4     "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 5 <hibernate-mapping>    
 6     <class name="com.Elastic.HibernateDemo4.ivy.entity.Dept" table="dept">
 7         <!-- 主键 -->
 8         <id name="deptId" column="deptid">
 9             <!-- 主键生成策略 -->
10             <generator class="increment"></generator>
11         </id>
12         <property name="deptName" column="deptname"></property>
13         <property name="location" column="location"></property>
14         
15         <!-- 多个员工 -->
16         <set name="emps" cascade="all" inverse="true" order-by="empNo desc" lazy="extra">
17             <key column="deptid"></key>
18             <one-to-many class="com.Elastic.HibernateDemo4.ivy.entity.Emp"/>
19         </set>
20     </class>
21 </hibernate-mapping>

a1.Emp

 1 package com.Elastic.HibernateDemo3.ivy.entity;
 2 import java.io.Serializable;
 3 public class Emp implements Serializable {
 4     private static final long serialVersionUID = -6182713107749938132L;
 5     private Integer empNo;
 6     private String empName;
 7     private Integer deptId;
 8     
 9     private Dept dept;
10     
11     public Integer getDeptId() {
12         return deptId;
13     }
14     public void setDeptId(Integer deptId) {
15         this.deptId = deptId;
16     }
17     public Dept getDept() {
18         return dept;
19     }
20     public void setDept(Dept dept) {
21         this.dept = dept;
22     }
23     public Integer getEmpNo() {
24         return empNo;
25     }
26     public void setEmpNo(Integer empNo) {
27         this.empNo = empNo;
28     }
29     public String getEmpName() {
30         return empName;
31     }
32     public void setEmpName(String empName) {
33         this.empName = empName;
34     }
35 }

b1.Emp.hbm.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE hibernate-mapping PUBLIC
 3     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 4     "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 5 <hibernate-mapping>
 6     <class name="com.Elastic.HibernateDemo4.ivy.entity.Emp" table="emp">
 7         <!-- 主键 -->
 8         <id name="empNo" column="empNo">
 9             <!-- 主键生成策略 -->
10             <generator class="increment"></generator>
11         </id>
12         <property name="empName" column="empName"></property>
13         <property name="deptId" column="deptId" insert="false" update="false"></property>
14         
15         <!-- 多对一的关系(多个员工属于一个部门) -->
16         <many-to-one name="dept" class="com.Elastic.HibernateDemo4.ivy.entity.Dept" column="deptId" lazy="proxy"></many-to-one>
17     </class>
18     
19     <!-- 配置HQL命名查询 -->
20     <query name="findEmpByDeptName">
21         <![CDATA[
22         from Emp e where e.dept.deptName = :deptname and e.empName = :ename
23         ]]>
24     </query>
25     
26     <!-- 配置原生的SQL语句 -->
27     <sql-query name="findEmp">
28         <return alias="e" class="com.Elastic.HibernateDemo4.ivy.entity.Emp"></return>
29         select * from emp e inner join dept d on e.deptId = d.deptId where e.empName = :ename and d.deptName = :deptname
30     </sql-query>
31 </hibernate-mapping>

2.hibernate.cfg.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 
 3 <!DOCTYPE hibernate-configuration PUBLIC
 4     "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
 5     "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
 6 <hibernate-configuration>
 7     <session-factory>
 8         <!-- 连接数据库 -->
 9         <property name="connection.url">jdbc:mysql://localhost:3306/hibernatedb</property>
10         <property name="connection.username">root</property>
11         <property name="connection.password">root</property>
12         <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
13         <property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
14         <property name="show_sql">true</property>
15         <property name="format_sql">true</property>
16         
17         <!-- 数据库对应的实体类的映射文件路径 -->
18         <mapping resource="com/Elastic/HibernateDemo4/ivy/entity/Dept.hbm.xml"></mapping>
19         <mapping resource="com/Elastic/HibernateDemo4/ivy/entity/Emp.hbm.xml"></mapping>
20         
21     </session-factory>
22 </hibernate-configuration>

3.util包
a.HibernateUtil

 1 package com.Elastic.HibernateDemo4.ivy.util;
 2 import org.hibernate.Session;
 3 import org.hibernate.SessionFactory;
 4 import org.hibernate.cfg.Configuration;
 5 public final class HibernateUtil {
 6     private static Configuration cfg = null;
 7     private static SessionFactory sessionFactory = null;
 8     
 9     //本地线程
10     public static ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
11     
12     static{
13         cfg = new Configuration().configure();
14         sessionFactory = cfg.buildSessionFactory();
15     }
16     
17     public static Session getSession(){
18         Session session = threadLocal.get();
19         if (null == session || !session.isOpen()) {
20             session = sessionFactory.openSession();
21             threadLocal.set(session);
22         }
23         return session;
24     }
25 }

4.test包
a.对象查询的基本操作

 1 package com.Elastic.HibernateDemo4.ivy.test;
 2 import java.util.ArrayList;
 3 import java.util.HashMap;
 4 import java.util.List;
 5 import java.util.Map;
 6 import java.util.Set;
 7 import org.hibernate.Criteria;
 8 import org.hibernate.FetchMode;
 9 import org.hibernate.Session;
10 import org.hibernate.criterion.DetachedCriteria;
11 import org.hibernate.criterion.MatchMode;
12 import org.hibernate.criterion.Order;
13 import org.hibernate.criterion.Projection;
14 import org.hibernate.criterion.Projections;
15 import org.hibernate.criterion.Property;
16 import org.hibernate.criterion.Restrictions;
17 import org.hibernate.transform.ResultTransformer;
18 import com.Elastic.HibernateDemo4.ivy.entity.Dept;
19 import com.Elastic.HibernateDemo4.ivy.entity.Emp;
20 import com.Elastic.HibernateDemo4.ivy.util.HibernateUtil;
21 import com.sun.org.apache.xalan.internal.xsltc.util.IntegerArray;
22 public class Test {
23     public static void main(String[] args) {
24         Session session = HibernateUtil.getSession();
25         Criteria criteria = session.createCriteria(Dept.class);
26         
27         //查询在1楼的所有部门
28         criteria.add(Restrictions.eq("location", "1楼"));
29         
30         //查询1楼的所有部门
31         criteria.add(Restrictions.like("location", "1楼"));
32         
33         //查询含1的楼层的所有部门
34         criteria.add(Restrictions.like("location", "1", MatchMode.ANYWHERE));
35         
36         //查询部门编号为1或者位置在5楼的部门
37         criteria.add(Restrictions.or(Restrictions.eq("deptId", 1), Restrictions.eq("location", "5楼")));
38         
39         //查询部门编号为1或者4的部门
40         //in:第二个参数（字段值）数组或集合
41         criteria.add(Restrictions.in("deptId", new Integer[]{1, 4}));
42         
43         //集合
44         List<Integer> params = new ArrayList<Integer>();
45         params.add(1);
46         params.add(4);
47         criteria.add(Restrictions.in("deptId", params));
48         
49         //返回集合（若没条件，就返回所有的数据）
50         List<Dept> depts = criteria.list();
51         for (Dept dept : depts) {
52             System.out.println("部门编号：" + dept.getDeptId() + ",部门名称：" + dept.getDeptName() + ",部门位置：" + dept.getLocation() + "\n");
53         }
54     }
55 }

b.多条件查询

 1 package com.Elastic.HibernateDemo4.ivy.test;
 2 import java.util.ArrayList;
 3 import java.util.HashMap;
 4 import java.util.List;
 5 import java.util.Map;
 6 import java.util.Set;
 7 import org.hibernate.Criteria;
 8 import org.hibernate.FetchMode;
 9 import org.hibernate.Session;
10 import org.hibernate.criterion.DetachedCriteria;
11 import org.hibernate.criterion.MatchMode;
12 import org.hibernate.criterion.Order;
13 import org.hibernate.criterion.Projection;
14 import org.hibernate.criterion.Projections;
15 import org.hibernate.criterion.Property;
16 import org.hibernate.criterion.Restrictions;
17 import org.hibernate.transform.ResultTransformer;
18 import com.Elastic.HibernateDemo4.ivy.entity.Dept;
19 import com.Elastic.HibernateDemo4.ivy.entity.Emp;
20 import com.Elastic.HibernateDemo4.ivy.util.HibernateUtil;
21 import com.sun.org.apache.xalan.internal.xsltc.util.IntegerArray;
22 public class Test {
23     public static void main(String[] args) {
24         Session session = HibernateUtil.getSession();
25         Criteria criteria = session.createCriteria(Dept.class);
26         //查询在5楼且部门编号为1的部门
27         Map<String, Object> params = new HashMap<String, Object>();
28         params.put("location", "5楼");
29         params.put("deptId", 1);
30         for (String key : params.keySet()) {
31             criteria.add(Restrictions.eq(key, params.get(key)));
32         }
33         //返回集合（若没条件，就返回所有的数据）
34         List<Dept> depts = criteria.list();
35         for (Dept dept : depts) {
36             System.out.println("部门编号：" + dept.getDeptId() + ",部门名称：" + dept.getDeptName() + ",部门位置：" + dept.getLocation() + "\n");
37         }
38     }
39 }

c.排序

 1 package com.Elastic.HibernateDemo4.ivy.test;
 2 import java.util.ArrayList;
 3 import java.util.HashMap;
 4 import java.util.List;
 5 import java.util.Map;
 6 import java.util.Set;
 7 import org.hibernate.Criteria;
 8 import org.hibernate.FetchMode;
 9 import org.hibernate.Session;
10 import org.hibernate.criterion.DetachedCriteria;
11 import org.hibernate.criterion.MatchMode;
12 import org.hibernate.criterion.Order;
13 import org.hibernate.criterion.Projection;
14 import org.hibernate.criterion.Projections;
15 import org.hibernate.criterion.Property;
16 import org.hibernate.criterion.Restrictions;
17 import org.hibernate.transform.ResultTransformer;
18 import com.Elastic.HibernateDemo4.ivy.entity.Dept;
19 import com.Elastic.HibernateDemo4.ivy.entity.Emp;
20 import com.Elastic.HibernateDemo4.ivy.util.HibernateUtil;
21 import com.sun.org.apache.xalan.internal.xsltc.util.IntegerArray;
22 public class Test {
23     public static void main(String[] args) {
24         Session session = HibernateUtil.getSession();
25         Criteria criteria = session.createCriteria(Dept.class);
26         //按部门编号降序排列
27         criteria.addOrder(Order.desc("deptId"));
28         //按部门位置升序排列
29         criteria.addOrder(Order.asc("location"));
30         //中文排序？？？
31         criteria.addOrder(Order.desc("deptName"));
32         //返回集合（若没条件，就返回所有的数据）
33         List<Dept> depts = criteria.list();
34         for (Dept dept : depts) {
35             System.out.println("部门编号：" + dept.getDeptId() + ",部门名称：" + dept.getDeptName() + ",部门位置：" + dept.getLocation() + "\n");
36         }
37     }
38 }

d.投影

 1 package com.Elastic.HibernateDemo4.ivy.test;
 2 import java.util.ArrayList;
 3 import java.util.HashMap;
 4 import java.util.List;
 5 import java.util.Map;
 6 import java.util.Set;
 7 import org.hibernate.Criteria;
 8 import org.hibernate.FetchMode;
 9 import org.hibernate.Session;
10 import org.hibernate.criterion.DetachedCriteria;
11 import org.hibernate.criterion.MatchMode;
12 import org.hibernate.criterion.Order;
13 import org.hibernate.criterion.Projection;
14 import org.hibernate.criterion.Projections;
15 import org.hibernate.criterion.Property;
16 import org.hibernate.criterion.Restrictions;
17 import org.hibernate.transform.ResultTransformer;
18 import com.Elastic.HibernateDemo4.ivy.entity.Dept;
19 import com.Elastic.HibernateDemo4.ivy.entity.Emp;
20 import com.Elastic.HibernateDemo4.ivy.util.HibernateUtil;
21 import com.sun.org.apache.xalan.internal.xsltc.util.IntegerArray;
22 public class Test {
23     public static void main(String[] args) {
24         Session session = HibernateUtil.getSession();
25         Criteria criteria = session.createCriteria(Dept.class);
26         //查询总条数
27         criteria.setProjection(Projections.rowCount());
28         int total = Integer.parseInt(criteria.uniqueResult().toString());
29         System.out.println(total);
30         System.out.println("记录数：" + criteria.list().iterator().next());
31         
32         //取消查询总条数
33         criteria.setProjection(null);
34     }
35 }

e.分页

 1 package com.Elastic.HibernateDemo4.ivy.test;
 2 import java.util.ArrayList;
 3 import java.util.HashMap;
 4 import java.util.List;
 5 import java.util.Map;
 6 import java.util.Set;
 7 import org.hibernate.Criteria;
 8 import org.hibernate.FetchMode;
 9 import org.hibernate.Session;
10 import org.hibernate.criterion.DetachedCriteria;
11 import org.hibernate.criterion.MatchMode;
12 import org.hibernate.criterion.Order;
13 import org.hibernate.criterion.Projection;
14 import org.hibernate.criterion.Projections;
15 import org.hibernate.criterion.Property;
16 import org.hibernate.criterion.Restrictions;
17 import org.hibernate.transform.ResultTransformer;
18 import com.Elastic.HibernateDemo4.ivy.entity.Dept;
19 import com.Elastic.HibernateDemo4.ivy.entity.Emp;
20 import com.Elastic.HibernateDemo4.ivy.util.HibernateUtil;
21 import com.sun.org.apache.xalan.internal.xsltc.util.IntegerArray;
22 public class Test {
23     public static void main(String[] args) {
24         Session session = HibernateUtil.getSession();
25         Criteria criteria = session.createCriteria(Dept.class);
26         criteria.setFirstResult(0);
27         criteria.setMaxResults(2);
28         
29         //查询部门编号最大的部门信息
30         criteria.addOrder(Order.desc("deptId"));
31         criteria.setFirstResult(0);
32         criteria.setMaxResults(1);
33         Dept d = (Dept) criteria.uniqueResult();
34         System.out.println("部门编号：" + d.getDeptId() + ",部门名称：" + d.getDeptName() + ",部门位置：" + d.getLocation() + "\n");
35     }
36 }

f.关联

 1 package com.Elastic.HibernateDemo4.ivy.test;
 2 import java.util.ArrayList;
 3 import java.util.HashMap;
 4 import java.util.List;
 5 import java.util.Map;
 6 import java.util.Set;
 7 import org.hibernate.Criteria;
 8 import org.hibernate.FetchMode;
 9 import org.hibernate.Session;
10 import org.hibernate.criterion.DetachedCriteria;
11 import org.hibernate.criterion.MatchMode;
12 import org.hibernate.criterion.Order;
13 import org.hibernate.criterion.Projection;
14 import org.hibernate.criterion.Projections;
15 import org.hibernate.criterion.Property;
16 import org.hibernate.criterion.Restrictions;
17 import org.hibernate.transform.ResultTransformer;
18 import com.Elastic.HibernateDemo4.ivy.entity.Dept;
19 import com.Elastic.HibernateDemo4.ivy.entity.Emp;
20 import com.Elastic.HibernateDemo4.ivy.util.HibernateUtil;
21 import com.sun.org.apache.xalan.internal.xsltc.util.IntegerArray;
22 public class Test {
23     public static void main(String[] args) {
24         Session session = HibernateUtil.getSession();
25         Criteria criteria = session.createCriteria(Dept.class);
26         //查询黎明所在的部门
27         Criteria empCriteria = criteria.createAlias("emps", "emp");
28         empCriteria.add(Restrictions.eq("emp.empName", "黎明"));
29         List<Dept> depts = empCriteria.list();
30         for (Dept dept : depts) {
31             System.out.println("部门编号：" + dept.getDeptId() + ",部门名称：" + dept.getDeptName() + ",部门位置：" + dept.getLocation() + "\n");
32         }
33         
34         //只查询部门名称
35         //org.hibernate.criterion.Property
36         /*criteria.setProjection(Property.forName("deptName"));
37         List<String> names = criteria.list();
38         for (String name : names) {
39             System.out.println(name);
40         }*/
41         
42         //只查询部门的名称和编号
43         /*criteria.setProjection(Projections.projectionList()
44                 .add(Property.forName("deptName"))
45                 .add(Property.forName("deptId")));
46         List<Object[]> datas = criteria.list();
47         for (Object[] objects : datas) {
48             System.out.println(objects[0].toString() + objects[1]);
49         }*/
50         
51         //统计部门编号的平均值
52         /*criteria.setProjection(Projections.avg("deptId"));
53         Object result = criteria.uniqueResult();
54         System.out.println(result);*/
55     }
56 }

g.DetachedCriteria查询

 1 package com.Elastic.HibernateDemo4.ivy.test;
 2 import java.util.ArrayList;
 3 import java.util.HashMap;
 4 import java.util.List;
 5 import java.util.Map;
 6 import java.util.Set;
 7 import org.hibernate.Criteria;
 8 import org.hibernate.FetchMode;
 9 import org.hibernate.Session;
10 import org.hibernate.criterion.DetachedCriteria;
11 import org.hibernate.criterion.MatchMode;
12 import org.hibernate.criterion.Order;
13 import org.hibernate.criterion.Projection;
14 import org.hibernate.criterion.Projections;
15 import org.hibernate.criterion.Property;
16 import org.hibernate.criterion.Restrictions;
17 import org.hibernate.transform.ResultTransformer;
18 import com.Elastic.HibernateDemo4.ivy.entity.Dept;
19 import com.Elastic.HibernateDemo4.ivy.entity.Emp;
20 import com.Elastic.HibernateDemo4.ivy.util.HibernateUtil;
21 import com.sun.org.apache.xalan.internal.xsltc.util.IntegerArray;
22 public class Test {
23     public static void main(String[] args) {
24         Session session = HibernateUtil.getSession();
25         Criteria criteria = session.createCriteria(Dept.class);
26         //查询销售部的王五的所在部门的楼层
27         //方法1
28         DetachedCriteria detachedCriteria = DetachedCriteria.forClass(Dept.class);
29         detachedCriteria.add(Restrictions.eq("deptName", "销售部"));
30         DetachedCriteria empDetachedCriteria = detachedCriteria.createCriteria("emps");
31         empDetachedCriteria.add(Restrictions.eq("empName", "王五"));
32         Criteria deptCriteria = detachedCriteria.getExecutableCriteria(session);
33         List<Dept> depts = deptCriteria.list();
34         for (Dept dept : depts) {
35             System.out.println(dept.getLocation());
36         }
37         
38         //方法2
39         criteria.setFetchMode("emps", FetchMode.JOIN);
40         List<Dept> list = criteria.list();
41         for (Dept dept : list) {
42             System.out.println(dept.getDeptName());
43             Set<Emp> emps = dept.getEmps();
44             for (Emp emp : emps) {
45                 System.out.println("\t" + emp.getEmpName());
46             }
47         }
48     }
49 }

==============================注解===============================
Hibernate提供了Hibernate Annotations扩展包，使用注解完成映射

优势：
   替换hbm.xml文件。利用注解后，可不用定义持久化类对应的*.hbm.xml文件。直接以注解方式写入在持久化类中实现

步骤：
   1.添加jar包
   2.使用注解配置持久化类以及对象关联关系
   3.使用AnnotationConfiguration建立SessionFactory
   4.在Hibernate配置文件（hibernate.cfg.xml）中声明持久化类

配置持久化类:
   注解               含义和作用
   @Entity           将一个类声明为一个持久化类
   @Id               声明了持久化类的标识属性
   @GeneratedValue   定义标识属性值的生成策略
   @Table           为持久化类映射指定表
   @Column           将属性映射到列（字段）
   @Lob           将属性持久化为Blob或Clob类型
   @Transient       将忽略这些属性，不用持久化到数据库

配置关联关系:
   注解           含义和作用
   @OneToOne   建立持久化类之间的一对一关联关系
   @OneToMany   建立持久化类之间的一对多关联关系
   @ManyToOne   建立持久化类之间的多对一关联关系
   @ManyToMany   建立持久化类之间的多对多关联关系

配置命名查询--@NamedQuery
   范例：
   @Entity
   @Table(name = "EMP")
   @NamedQuery(name = "selectEmp", query = "from Emp where empName like :ename")
   public class Emp implements java.io.Serializable {
       //缺省其他代码
   }

=================================同综合范例================================
1.entity包
a.Dept

 1 package com.Elastic.HibernateDemo4.ivy.entity;
 2 import java.io.Serializable;
 3 import java.util.Set;
 4 import javax.persistence.CascadeType;
 5 import javax.persistence.Column;
 6 import javax.persistence.Entity;
 7 import javax.persistence.FetchType;
 8 import javax.persistence.Id;
 9 import javax.persistence.OneToMany;
10 import javax.persistence.Table;
11 @Entity
12 @Table(name = "dept")
13 public class Dept implements Serializable {
14 
15     @Id
16     /**
17      * nullable:是否为空
18      * nullable = false：非空
19      */
20     @Column(name = "deptid", nullable = false)
21     private Integer deptId;
22     @Column(name = "deptname", nullable = false)
23     private String deptName;
24 
25     private String location;
26 
27     // 多对一: 一个部门有多个员工
28     /**
29      * @OneToMany--
30      * mappedBy：指定“多”方的关联属性
31      * 在双向关联中，有且只有一端作为主体端，负责维护更新。
32      * 对于不需要维护这种关系的从表通过mappedBy声明，指向另一主体的关联性，相当于inverse="true"
33      * fetch：指定关联关系获取方式，即是否采用延迟加载
34      * cascade：指定级联操作
35      * 1.CascadeType.REMOVE：级联删除
36      * 2.CascadeType.PERSIST：级联新建
37      * 3.CascadeType.MERGE：级联更新
38      * 4.CascadeType.REFRESH：级联刷新
39      * 5.CascadeType.ALL：包含所有级联操作
40      * targetEntity：指定关联的实体类
41      */
42     @OneToMany(cascade = CascadeType.ALL, targetEntity = Emp.class, mappedBy = "deptId", fetch = FetchType.LAZY)
43     private Set<Emp> emps;
44 
45     public Integer getDeptId() {
46         return deptId;
47     }
48 
49     public void setDeptId(Integer deptId) {
50         this.deptId = deptId;
51     }
52 
53     public String getDeptName() {
54         return deptName;
55     }
56 
57     public void setDeptName(String deptName) {
58         this.deptName = deptName;
59     }
60 
61     public String getLocation() {
62         return location;
63     }
64 
65     public void setLocation(String location) {
66         this.location = location;
67     }
68 
69     public Set<Emp> getEmps() {
70         return emps;
71     }
72 
73     public void setEmps(Set<Emp> emps) {
74         this.emps = emps;
75     }
76 
77 }

b.Emp

 1 package com.Elastic.HibernateDemo4.ivy.entity;
 2 import java.io.Serializable;
 3 import javax.persistence.Column;
 4 import javax.persistence.Entity;
 5 import javax.persistence.Id;
 6 import javax.persistence.JoinColumn;
 7 import javax.persistence.ManyToOne;
 8 import javax.persistence.NamedNativeQuery;
 9 import javax.persistence.NamedQuery;
10 import javax.persistence.Table;
11 @Entity
12 @Table(name = "emp")
13 
14 //命名查询@NamedQuery：name属性：名字，query属性：hql语句
15 @NamedQuery(name="findHql",query="from Emp e where e.dept.deptName = :deptname and e.empName = :ename")
16 
17 //原生命名查询@NamedNativeQuery：name属性：名字，query属性：sql语句
18 @NamedNativeQuery(name="findSql",query="select * from emp e inner join dept d on e.deptId = d.deptId where e.empName = :ename and d.deptName = :deptname",resultClass=Emp.class)
19 public class Emp implements Serializable {
20 
21     @Id
22     private Integer empNo;
23     private String empName;
24 
25     /**
26      * insertable：是否可插入。
27      * false 不能；true 能
28      * updatable：是否可更新
29      * false 不能；true 能
30      *
31      * 这里的deptId是主表dept的主键，所以在从表中不能插入、更新deptId
32      */
33     @Column(insertable = false, updatable = false)
34     private Integer deptId;
35 
36     // 部门对象
37     /**
38      * @oneToMany的”多“方，通过@JoinColumn指定”多“方定义的外键字段
39      */
40     @JoinColumn(name = "deptId")
41     
42     //多个员工对应一个部门@ManyToOne
43     @ManyToOne(targetEntity = Dept.class)
44     private Dept dept;
45 
46     public Integer getEmpNo() {
47         return empNo;
48     }
49 
50     public void setEmpNo(Integer empNo) {
51         this.empNo = empNo;
52     }
53 
54     public String getEmpName() {
55         return empName;
56     }
57 
58     public void setEmpName(String empName) {
59         this.empName = empName;
60     }
61 
62     public Integer getDeptId() {
63         return deptId;
64     }
65 
66     public void setDeptId(Integer deptId) {
67         this.deptId = deptId;
68     }
69 
70     public Dept getDept() {
71         return dept;
72     }
73 
74     public void setDept(Dept dept) {
75         this.dept = dept;
76     }
77 
78 }

2.hibernate.cfg.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 
 3 <!DOCTYPE hibernate-configuration PUBLIC
 4     "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
 5     "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
 6 
 7 <hibernate-configuration>
 8     <session-factory>
 9         <!-- 连接数据库 -->
10         <property name="connection.url">jdbc:mysql://localhost:3306/hibernatedb</property>
11         <property name="connection.username">root</property>
12         <property name="connection.password">root</property>
13         <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
14         <property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
15         <property name="show_sql">true</property>
16         <property name="format_sql">true</property>
17         
18         <!-- 注解 -->
19         <mapping class="com.Elastic.HibernateDemo4.ivy.entity.Dept"></mapping>
20         <mapping class="com.Elastic.HibernateDemo4.ivy.entity.Emp"></mapping>
21         
22     </session-factory>
23 </hibernate-configuration>

posted @ 2016-06-26 17:45 Ivy_Xu 阅读(618) 评论(0) 编辑收藏举报

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