(十)Hibernate 查询方式
所有项目导入对应的hibernate的jar包、mysql的jar包和添加每次都需要用到的HibernateUtil.java
第一节:Hibernate 查询方式简介
1,导航对象图查询方式;
2,OID 查询方式;
3,本地SQL 查询方式;
4,HQL 查询方式;
5,QBC 查询方式;(Query By Criteria)
第二节:本地SQL 查询方式
Student.java
package com.wishwzp.model; public class Student { private int id;
private String name;
private int age; public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";
} }
Student.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="com.wishwzp.model"> <class name="Student" table="t_student">
<id name="id" column="stuId">
<generator class="native"></generator>
</id> <property name="name" column="stuName"></property>
<property name="age" column="stuAge"></property>
</class> </hibernate-mapping>
hibernate.cfg.xml
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <!--数据库连接设置 -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property>
<property name="connection.username">root</property>
<property name="connection.password">123456</property> <!-- 方言 -->
<property name="dialect">org.hibernate.dialect.MySQL5Dialect</property> <!-- 控制台显示SQL -->
<property name="show_sql">true</property> <!-- 自动更新表结构 -->
<property name="hbm2ddl.auto">update</property> <mapping resource="com/wishwzp/model/Student.hbm.xml"/> </session-factory> </hibernate-configuration>
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testSQLQuery() { } }
运行结果生成了数据库信息:
我们插入一些数据:
再次写代码查询里面的数据:
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testSQLQuery() {
String sql="select * from t_student";
Query query=session.createSQLQuery(sql).addEntity(Student.class);
List studentList=query.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
} }
运行结果显示:
我们写一个带参数的查询语句查询:
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testSQLQuery2() {
String sql="select * from t_student where stuName like :stuName and stuAge=:stuAge";
Query query=session.createSQLQuery(sql).addEntity(Student.class);
query.setString("stuName", "张%");
query.setInteger("stuAge", 10);
List studentList=query.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
} }
运行结果显示:
第三节:HQL 查询方式
HQL(Hibernate Query Language)是面向对象的查询语言;是使用最广的一种查询方式;
1,普通查询;
2,带条件查询;
3,使用别名;
4,对结果排序;
5,分页查询;
6,查询单个对象;
7,链式写法;
1,普通查询;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testHQLQuery() {
String hql="from Student";
Query query=session.createQuery(hql);
List<Student> studentList=(List<Student>)query.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
} }
运行结果显示:
2,带条件查询;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testHQLQuery2() {
String hql="from Student where name like :stuName and age=:stuAge";
Query query=session.createQuery(hql);
query.setString("stuName", "张%");
query.setInteger("stuAge", 10);
List<Student> studentList=(List<Student>)query.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
} }
运行结果显示:
Hibernate: select student0_.stuId as stuId1_0_, student0_.stuName as stuName2_0_, student0_.stuAge as stuAge3_0_ from t_student student0_ where (student0_.stuName like ?) and student0_.stuAge=?
Student [id=1, name=张三, age=10]
3,使用别名;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testHQLQuery3() {
String hql="from Student as s where s.name like :stuName and s.age=:stuAge";
Query query=session.createQuery(hql);
query.setString("stuName", "张%");
query.setInteger("stuAge", 10);
List<Student> studentList=(List<Student>)query.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
} }
运行结果显示:
Hibernate: select student0_.stuId as stuId1_0_, student0_.stuName as stuName2_0_, student0_.stuAge as stuAge3_0_ from t_student student0_ where (student0_.stuName like ?) and student0_.stuAge=?
Student [id=1, name=张三, age=10]
4,对结果排序;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testHQLQuery4() {
String hql="from Student order by age desc";
Query query=session.createQuery(hql);
List<Student> studentList=(List<Student>)query.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
} }
运行结果显示:
Hibernate: select student0_.stuId as stuId1_0_, student0_.stuName as stuName2_0_, student0_.stuAge as stuAge3_0_ from t_student student0_ order by student0_.stuAge desc
Student [id=2, name=李四, age=15]
Student [id=3, name=王五, age=13]
Student [id=1, name=张三, age=10]
5,分页查询;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testHQLQuery5() {
String hql="from Student";
Query query=session.createQuery(hql);
query.setFirstResult(1);
query.setMaxResults(2);
List<Student> studentList=(List<Student>)query.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
} }
运行结果显示:
Hibernate: select student0_.stuId as stuId1_0_, student0_.stuName as stuName2_0_, student0_.stuAge as stuAge3_0_ from t_student student0_ limit ?, ?
Student [id=2, name=李四, age=15]
Student [id=3, name=王五, age=13]
6,查询单个对象;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testHQLQuery6() {
String hql="from Student";
Query query=session.createQuery(hql);
query.setFirstResult(1);
query.setMaxResults(1);
Student student=(Student)query.uniqueResult();
System.out.println(student);
} }
运行结果显示:
Hibernate: select student0_.stuId as stuId1_0_, student0_.stuName as stuName2_0_, student0_.stuAge as stuAge3_0_ from t_student student0_ limit ?, ?
Student [id=2, name=李四, age=15]
7,链式写法;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testHQLQuery7() {
String hql="from Student as s where s.name like :stuName and s.age=:stuAge";
Query query=session.createQuery(hql);
List<Student> studentList=(List<Student>)query
.setString("stuName", "张%")
.setInteger("stuAge", 10)
.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
}
}
运行结果显示:
Hibernate: select student0_.stuId as stuId1_0_, student0_.stuName as stuName2_0_, student0_.stuAge as stuAge3_0_ from t_student student0_ where (student0_.stuName like ?) and student0_.stuAge=?
Student [id=1, name=张三, age=10]
第四节:QBC 查询方式
QBC 查询方式(Query By Criteria)是用一套接口来实现的查询方式;
1,普通查询;
2,带条件查询;
3,对结果排序;
4,分页查询;
5,查询单个对象;
6,链式写法;
1,普通查询;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Restrictions;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testQBCQuery1(){
Criteria criteria=session.createCriteria(Student.class);
List<Student> studentList=criteria.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
} }
运行结果显示:
Hibernate: select this_.stuId as stuId1_0_0_, this_.stuName as stuName2_0_0_, this_.stuAge as stuAge3_0_0_ from t_student this_
Student [id=1, name=张三, age=10]
Student [id=2, name=李四, age=15]
Student [id=3, name=王五, age=13]
2,带条件查询;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Restrictions;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testQBCQuery2(){
Criteria criteria=session.createCriteria(Student.class);
Criterion c1=Restrictions.like("name", "张%");
Criterion c2=Restrictions.eq("age", 10);
criteria.add(c1);
criteria.add(c2);
List<Student> studentList=criteria.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
} }
运行结果显示:
Hibernate: select this_.stuId as stuId1_0_0_, this_.stuName as stuName2_0_0_, this_.stuAge as stuAge3_0_0_ from t_student this_ where this_.stuName like ? and this_.stuAge=?
Student [id=1, name=张三, age=10]
3,对结果排序;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Restrictions;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testQBCQuery3(){
Criteria criteria=session.createCriteria(Student.class);
criteria.addOrder(Order.desc("age"));
List<Student> studentList=criteria.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
} }
运行结果显示:
Hibernate: select this_.stuId as stuId1_0_0_, this_.stuName as stuName2_0_0_, this_.stuAge as stuAge3_0_0_ from t_student this_ order by this_.stuAge desc
Student [id=2, name=李四, age=15]
Student [id=3, name=王五, age=13]
Student [id=1, name=张三, age=10]
4,分页查询;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Restrictions;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testQBCQuery4(){
Criteria criteria=session.createCriteria(Student.class);
criteria.setFirstResult(2);
criteria.setMaxResults(2);
List<Student> studentList=criteria.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
} }
运行结果显示:
Hibernate: select this_.stuId as stuId1_0_0_, this_.stuName as stuName2_0_0_, this_.stuAge as stuAge3_0_0_ from t_student this_ limit ?, ?
Student [id=3, name=王五, age=13]
5,查询单个对象;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Restrictions;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testQBCQuery5(){
Criteria criteria=session.createCriteria(Student.class);
criteria.setFirstResult(2);
criteria.setMaxResults(1);
Student student=(Student)criteria.uniqueResult();
System.out.println(student);
} }
运行结果显示:
Hibernate: select this_.stuId as stuId1_0_0_, this_.stuName as stuName2_0_0_, this_.stuAge as stuAge3_0_0_ from t_student this_ limit ?, ?
Student [id=3, name=王五, age=13]
6,链式写法;
StudentTest.java
package com.wishwzp.service; import java.util.Iterator;
import java.util.List; import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Restrictions;
import org.junit.After;
import org.junit.Before;
import org.junit.Test; import com.wishwzp.model.Student;
import com.wishwzp.util.HibernateUtil; public class StudentTest { private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
private Session session; @Before
public void setUp() throws Exception {
session=sessionFactory.openSession(); // 生成一个session
session.beginTransaction(); // 开启事务
} @After
public void tearDown() throws Exception {
session.getTransaction().commit(); // 提交事务
session.close(); // 关闭session
} @Test
public void testQBCQuery6(){
Criteria criteria=session.createCriteria(Student.class);
List<Student> studentList=criteria
.setFirstResult(0)
.setMaxResults(2)
.list();
Iterator it=studentList.iterator();
while(it.hasNext()){
Student s=(Student)it.next();
System.out.println(s);
}
} }
运行结果显示:
Hibernate: select this_.stuId as stuId1_0_0_, this_.stuName as stuName2_0_0_, this_.stuAge as stuAge3_0_0_ from t_student this_ limit ?
Student [id=1, name=张三, age=10]
Student [id=2, name=李四, age=15]
END
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