12.hibernate命名查询

1.创建如下javaweb项目结构





2.在项目的src下创建hibernate.cfg.xml主配置文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd" >
<hibernate-configuration>
<session-factory>
<property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
<property name="connection.url">jdbc:oracle:thin:@127.0.0.1:1521:orcl</property>
<property name="connection.username">scott</property>
<property name="connection.password">tiger</property>
<property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>
<property name="show_sql">true</property>
<property name="format_sql">true</property>
<mapping resource="com/entity/Dept.hbm.xml"/>
<mapping resource="com/entity/Emp.hbm.xml"/>
</session-factory>
</hibernate-configuration>

3.在项目的src下的com.util包下创建HibernateUtil.java

package com.util;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class HibernateUtil {
private static ThreadLocal<Session> thread=new ThreadLocal<Session>();
private static Configuration config=null;
private static SessionFactory factory=null;
/**
* 读取配置文件
*/
static{
try {
config=new Configuration().configure("/hibernate.cfg.xml");
factory=config.buildSessionFactory();
} catch (HibernateException e) {
System.out.println("读取配置文件失败或创建factory失败");
e.printStackTrace();
}
}
/**
* 打开session
* @return
*/
public static Session getSession(){
Session session =thread.get();
if(session==null){
session=factory.openSession();
thread.set(session);
}
return session;
}
/**
* 关闭session
*/
public static void closeSession(){
Session session =thread.get();
thread.set(null);
session.close();

}

}

4.在项目的src下的com.entity包下创建Dept.java

package com.entity;

import java.util.HashSet;
import java.util.Set;

public class Dept {
private Integer deptno;
private String dname;
private String loc;
private Set<Emp> emps =new HashSet<Emp>();

public Dept() {
}

public Dept(Integer deptno, String dname, String loc) {
this.deptno = deptno;
this.dname = dname;
this.loc = loc;
}

public Dept(Integer deptno, String dname, String loc, Set<Emp> emps) {
this.deptno = deptno;
this.dname = dname;
this.loc = loc;
this.emps = emps;
}
public Integer getDeptno() {
return deptno;
}
public void setDeptno(Integer deptno) {
this.deptno = deptno;
}
public String getDname() {
return dname;
}
public void setDname(String dname) {
this.dname = dname;
}
public String getLoc() {
return loc;
}
public void setLoc(String loc) {
this.loc = loc;
}
public Set<Emp> getEmps() {
return emps;
}
public void setEmps(Set<Emp> emps) {
this.emps = emps;
}

@Override
public String toString() {
return "Dept [deptno=" + deptno + ", dname=" + dname + ", loc=" + loc + "]";
}

}

5.在项目的src下的com.entity包下创建Emp.java

package com.entity;

public class Emp {
private Integer empno;
private String ename;
private String job;
private Integer sal;
private Dept dept;

public Emp() {
}

public Emp(Integer empno, String ename, String job, Integer sal) {
super();
this.empno = empno;
this.ename = ename;
this.job = job;
this.sal = sal;
}

public Emp(Integer empno, String ename, String job, Integer sal, Dept dept) {
super();
this.empno = empno;
this.ename = ename;
this.job = job;
this.sal = sal;
this.dept = dept;
}

public Integer getEmpno() {
return empno;
}

public void setEmpno(Integer empno) {
this.empno = empno;
}

public String getEname() {
return ename;
}

public void setEname(String ename) {
this.ename = ename;
}

public String getJob() {
return job;
}

public void setJob(String job) {
this.job = job;
}

public Integer getSal() {
return sal;
}

public void setSal(Integer sal) {
this.sal = sal;
}

public Dept getDept() {
return dept;
}

public void setDept(Dept dept) {
this.dept = dept;
}

@Override
public String toString() {
return "Emp [ empno=" + empno + ", ename=" + ename
+ ", job=" + job + ", sal=" + sal + "]";
}

}

6.在项目的src下的com.entity包下创建Dept.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping>
<class name="com.entity.Dept" table="DEPT">
<id name="deptno" type="java.lang.Integer" column="DEPTNO">
<generator class="assigned"/>
</id>
<property name="dname" type="java.lang.String" column="DNAME"/>
<property name="loc" type="java.lang.String" column="LOC"/>
<!-- 一对多 -->
<set name="emps" inverse="true" cascade="save-update">
<key column="DEPTNO"></key>
<one-to-many class="com.entity.Emp"/>
</set>
</class>

</hibernate-mapping>

7.在项目的src下的com.entity包下创建Emp.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping>
<class name="com.entity.Emp" table="EMP">
<id name="empno" type="java.lang.Integer" column="EMPNO">
<generator class="assigned"/>
</id>
<property name="ename" type="java.lang.String" column="ENAME"/>
<property name="job" type="java.lang.String" column="JOB"/>
<property name="sal" type="java.lang.Integer" column="SAL"/>
<!-- 多对一 -->
<many-to-one name="dept" class="com.entity.Dept" column="DEPTNO"/>
</class>

<!-- 命名查询节点 -->
<query name="findEmpByJob">
<!-- cdata节点放入hql语句,原生sql查询语句 -->
<![CDATA[
from Emp e where e.job=:pjob
]]>
</query>
</hibernate-mapping>

8.在项目的src下的com.dao包下创建DeptDao.java

package com.dao;

import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;

import com.entity.Emp;
import com.util.HibernateUtil;

public class EmpDao {

public static void main(String[] args) {
System.out.println("-----------1.关联查询-----------");
getEmp();

}

/**
*1.命名查询
*/
private static void getEmp() {
Session session=HibernateUtil.getSession();
/*根据映射文件的query节点的name属性值获取hql语句*/
Query query=session.getNamedQuery("findEmpByJob");
/*给命名参数赋值*/
//query.setString("pjob", "CLERK");
query.setParameter("pjob", "CLERK");
List<Emp> list=query.list();
for (Emp emp : list) {
System.out.println(emp.getDept().getDeptno());
System.out.println(emp);
}
HibernateUtil.closeSession();

}

}

9.运行结果如下：remdeme.txt

1.内连接
Hibernate:
select
dept0_.DEPTNO as DEPTNO0_0_,
emps1_.EMPNO as EMPNO1_1_,
dept0_.DNAME as DNAME0_0_,
dept0_.LOC as LOC0_0_,
emps1_.ENAME as ENAME1_1_,
emps1_.JOB as JOB1_1_,
emps1_.SAL as SAL1_1_,
emps1_.DEPTNO as DEPTNO1_1_
from
DEPT dept0_
inner join
EMP emps1_
on dept0_.DEPTNO=emps1_.DEPTNO
2.迫切内连接
select
dept0_.DEPTNO as DEPTNO0_0_,
emps1_.EMPNO as EMPNO1_1_,
dept0_.DNAME as DNAME0_0_,
dept0_.LOC as LOC0_0_,
emps1_.ENAME as ENAME1_1_,
emps1_.JOB as JOB1_1_,
emps1_.SAL as SAL1_1_,
emps1_.DEPTNO as DEPTNO1_1_,
emps1_.DEPTNO as DEPTNO0__,
emps1_.EMPNO as EMPNO0__
from
DEPT dept0_
inner join
EMP emps1_
on dept0_.DEPTNO=emps1_.DEPTNO
-------4.左连接-------
Hibernate:
select
dept0_.DEPTNO as DEPTNO0_0_,
emps1_.EMPNO as EMPNO1_1_,
dept0_.DNAME as DNAME0_0_,
dept0_.LOC as LOC0_0_,
emps1_.ENAME as ENAME1_1_,
emps1_.JOB as JOB1_1_,
emps1_.SAL as SAL1_1_,
emps1_.DEPTNO as DEPTNO1_1_
from
DEPT dept0_
left outer join
EMP emps1_
on dept0_.DEPTNO=emps1_.DEPTNO

-------5.迫切左连接-------
Hibernate:
select
distinct dept0_.DEPTNO as DEPTNO0_0_,
emps1_.EMPNO as EMPNO1_1_,
dept0_.DNAME as DNAME0_0_,
dept0_.LOC as LOC0_0_,
emps1_.ENAME as ENAME1_1_,
emps1_.JOB as JOB1_1_,
emps1_.SAL as SAL1_1_,
emps1_.DEPTNO as DEPTNO1_1_,
emps1_.DEPTNO as DEPTNO0__,
emps1_.EMPNO as EMPNO0__
from
DEPT dept0_
left outer join
EMP emps1_
on dept0_.DEPTNO=emps1_.DEPTNO
-------6.右连接-------
Hibernate:
select
dept0_.DEPTNO as DEPTNO0_0_,
emps1_.EMPNO as EMPNO1_1_,
dept0_.DNAME as DNAME0_0_,
dept0_.LOC as LOC0_0_,
emps1_.ENAME as ENAME1_1_,
emps1_.JOB as JOB1_1_,
emps1_.SAL as SAL1_1_,
emps1_.DEPTNO as DEPTNO1_1_
from
DEPT dept0_
right outer join
EMP emps1_
on dept0_.DEPTNO=emps1_.DEPTNO