Hibernate HQL多条件查询（四）
Hi，大家好，我是编程小6，很荣幸遇见你，我把这些年在开发过程中遇到的问题或想法写出来，今天说一说
Hibernate HQL多条件查询（四）,希望能够帮助你!!!。
目录
概述：
1、查询对象
查询结果：
2、分⻚查询
结果：
3、where 条件查询
结果：
4、模糊查询
结果：
5、order by
结果：
6、查询实体对象的属性
结果：
7、占位符
结果：
8、级联查询
结果：
概述：
HQL
：
Hibernate Query Language
，是
Hibernate
框架提供的⼀种查询机制，它和
SQL
类似，不同的
：
Hibernate Query Language
，是
Hibernate
框架提供的⼀种查询机制，它和
SQL
类似，不同的
是
HQL
是⾯向对象的查询语句，让开发者能够以⾯向对象的思想来编写查询语句，对
Java
编程是⼀种很友好的⽅式。
HQL
是⾯向对象的查询语句，让开发者能够以⾯向对象的思想来编写查询语句，对
Java
编程是⼀种很友好的⽅式。
HQL
不能直接参与数据库的交互，中间层语⾔。
不能直接参与数据库的交互，中间层语⾔。
Java ---
》
HQL ---
〉
Hibernate ---
》
SQL ---
〉
DB
》
HQL ---
〉
Hibernate ---
》
SQL ---
〉
DB
HQL
只能完成查询、修改、删除，新增是⽆法操作的。
只能完成查询、修改、删除，新增是⽆法操作的。
1、查询对象
查询表中所有数据，⾃动完成对象的封装，返回
List
集合。
List
集合。
HQL
进⾏查询，
from
关键字后⾯不能写表名，必须写表对应的实体类名。
进⾏查询，
from
关键字后⾯不能写表名，必须写表对应的实体类名。
//1、实体类 package com.southwind.entity; import lombok.Data; @Data public class People { private Integer id; private String name; private Double money; } <!--2、People.hbm.xml文件--> <?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <!--文件名的hbm就是hibernate-mapping 的缩写，在这里面完成类和表的映射--> <!-- class 就是指类，name就是指类名 table 就是指对应的表名,表customer里面有id和name两个字段--> <class name="com.southwind.entity.People" table="people"> <!-- 主键映射 name指的是实体类里面的属性：id type指的是id属性的类型--> <id name="id" type="java.lang.Integer"> <!--column是字段，指的是对应类里面id的表里面的名称--> <column name="id"></column> <!--这个是配置主键自增的方式，identity的意思就是自增--> <generator class="identity"></generator> </id> <!-- 下面继续配置类里面的其他信息，name type指的是name属性的类型--> <property name="name" type="java.lang.String"> <!--column是字段，指的是对应类里面name的表里面的名称--> <column name="name"></column> </property> <!-- 下面继续配置类里面的其他信息，money type指的是money属性的类型--> <property name="money" type="java.lang.Double"> <!--column是字段，指的是对应类里面money的表里面的名称--> <column name="money"></column> </property> </class> </hibernate-mapping> <!--3、hibernate.cfg.xml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> <!-- 核⼼配置：session-factory--> <!-- SessionFactory：针对单个数据库映射经过编译的内存镜像⽂件，将数据库转换为⼀个 Java 可以识别的镜像⽂件。--> <!-- 构建 SessionFactory ⾮常耗费资源，所以通常⼀个⼯程只需要创建⼀个 SessionFactory。--> <session-factory> <!-- datasource 数据源配置 --> <property name="connection.username">root</property> <property name="connection.password"></property> <property name="connection.driver_class">com.mysql.cj.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT</property> <!--?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT" />--> <!-- C3P0 连接池 --> <property name="hibernate.c3p0.acquire_increment">10</property> <!-- 每次不够的话就会增加的数量--> <property name="hibernate.c3p0.idle_test_period">10000</property> <!--释放资源时间的设置，s为单位--> <property name="hibernate.c3p0.timeout">5000</property> <!-- 超时时间--> <property name="hibernate.c3p0.max_size">30</property> <!-- 最大连接数--> <property name="hibernate.c3p0.min_size">5</property> <!-- 最小连接数--> <property name="hibernate.c3p0.max_statements">10</property> <!-- 最大线程数数--> <!-- 数据库⽅⾔ oracle或mysql--> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <!-- 打印SQL语句,固定写法 --> <property name="show_sql">true</property> <!-- 格式化SQL语句,固定写法 --> <property name="format_sql">true</property> <!-- 是否⾃动⽣成数据表--> <property name="hibernate.hbm2ddl.auto">update</property> <!-- create：每次加载hibernate时都会删除上一次的生成的表，然后根据你的model类再重新来生成新表， 哪怕两次没有任何改变也要这样执行，这就是导致数据库表数据丢失的一个重要原因。 create-drop ：每次加载hibernate时根据model类生成表，但是sessionFactory一关闭,表就自动删除。 update：最常用的属性，第一次加载hibernate时根据model类会自动建立起表的结构（前提是先建立好数据库）， 以后加载hibernate时根据 model类自动更新表结构，即使表结构改变了但表中的行仍然存在不会删除以前的行。 要注意的是当部署到服务器后，表结构是不会被马上建立起来的，是要等 应用第一次运行起来后才会。 validate ：每次加载hibernate时，验证创建数据库表结构，只会和数据库中的表进行比较，不会创建新表，但是会插入新值。 --> <!-- 注册实体关系映射文件 --> <mapping resource="com/southwind/entity/People.hbm.xml"></mapping> <mapping resource="com/southwind/entity/Customer.hbm.xml"></mapping> <mapping resource="com/southwind/entity/Orders.hbm.xml"></mapping> <mapping resource="com/southwind/entity/Account.hbm.xml"></mapping> <mapping resource="com/southwind/entity/Course.hbm.xml"></mapping> </session-factory> </hibernate-configuration> //4、test package com.southwind.test; import com.southwind.entity.Customer; import com.southwind.entity.Orders; import com.southwind.entity.People; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; import org.hibernate.query.Query; import java.util.List; public class Test11 { public static void main(String[] args) { //创建 Configuration Configuration configuration = new Configuration().configure(); //获取 SessionFactory SessionFactory sessionFactory = configuration.buildSessionFactory(); //获取 Session Session session = sessionFactory.openSession(); //查询对象 String hql = "from People"; Query query = session.createQuery(hql); List<People> list = query.list(); for(People people:list){ System.out.println(people); } //分⻚查询 // String hql = "from People"; // Query query = session.createQuery(hql); // query.setFirstResult(1);//设置起始下标 // query.setMaxResults(3);//设置截取⻓度 // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //where 条件查询 // String hql = "from People where id = 4"; // Query query = session.createQuery(hql); // People people = (People) query.uniqueResult(); // System.out.println(people); //模糊查询 // String hql = "from People where name like '%四%'"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //order by排序查询 // String hql = "from People order by id desc "; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //查询实体对象的属性，姓名 // String hql = "select name from People where id = 6"; // Query query = session.createQuery(hql); // String name = (String) query.uniqueResult(); // System.out.println(name); //占位符 // String hql = "from People where name = :name"; // Query query = session.createQuery(hql); // query.setString("name","张三"); // List<People> list = query.list(); // for (People people:list){ // System.out.println(people); // } //级联查询 // String hql1 = "from Customer where name = :name"; // Query query1 = session.createQuery(hql1); // query1.setString("name","张三"); // Customer customer = (Customer) query1.uniqueResult(); // String hql2 = "from Orders where customer = :customer"; // Query query2 = session.createQuery(hql2); // query2.setEntity("customer",customer); // List<Orders> list = query2.list(); // for(Orders orders:list){ // System.out.println(orders); // } session.close(); } } 查询结果：
2、分⻚查询
HQL
分⻚查询可以通过调⽤
query
的⽅法来完成。
分⻚查询可以通过调⽤
query
的⽅法来完成。
1、setFirstResult() 设置起始下标
2、setMaxResults() 设置截取⻓度
package com.southwind.test; import com.southwind.entity.People; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; import org.hibernate.query.Query; import java.util.List; public class Test11 { public static void main(String[] args) { //创建 Configuration Configuration configuration = new Configuration().configure(); //获取 SessionFactory SessionFactory sessionFactory = configuration.buildSessionFactory(); //获取 Session Session session = sessionFactory.openSession(); // String hql = "from People"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } String hql = "from People"; Query query = session.createQuery(hql); //从第一个开始，往后面3个 query.setFirstResult(1);//设置起始下标 query.setMaxResults(3);//设置截取⻓度 List<People> list = query.list(); for(People people:list){ System.out.println(people); } // String hql = "from People where id = 0"; // Query query = session.createQuery(hql); // People people = (People) query.uniqueResult(); // System.out.println(people); // String hql = "from People where name like '%三%'"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } // String hql = "from People order by id asc "; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } // String hql = "select name from People where id = 6"; // Query query = session.createQuery(hql); // String name = (String) query.uniqueResult(); // System.out.println(name); // String hql = "from People where name = :name"; // Query query = session.createQuery(hql); // query.setString("name","张三"); // List<People> list = query.list(); // for (People people:list){ // System.out.println(people); // } // String hql1 = "from Customer where name = :name"; // Query query1 = session.createQuery(hql1); // query1.setString("name","张三"); // Customer customer = (Customer) query1.uniqueResult(); // String hql2 = "from Orders where customer = :customer"; // Query query2 = session.createQuery(hql2); // query2.setEntity("customer",customer); // List<Orders> list = query2.list(); // for(Orders orders:list){ // System.out.println(orders); // } session.close(); } } 结果：
3、where 条件查询
HQL 直接追加 where 关键字作为查询条件，与 SQL 没有区别。
package com.southwind.test; import com.southwind.entity.People; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; import org.hibernate.query.Query; import java.util.List; public class Test11 { public static void main(String[] args) { //创建 Configuration Configuration configuration = new Configuration().configure(); //获取 SessionFactory SessionFactory sessionFactory = configuration.buildSessionFactory(); //获取 Session Session session = sessionFactory.openSession(); // String hql = "from People"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } // String hql = "from People"; // Query query = session.createQuery(hql); // query.setFirstResult(1);//设置起始下标 // query.setMaxResults(3);//设置截取⻓度 // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } String hql = "from People where id = 4"; Query query = session.createQuery(hql); People people = (People) query.uniqueResult(); System.out.println(people); // String hql = "from People where name like '%三%'"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } // String hql = "from People order by id asc "; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } // String hql = "select name from People where id = 6"; // Query query = session.createQuery(hql); // String name = (String) query.uniqueResult(); // System.out.println(name); // String hql = "from People where name = :name"; // Query query = session.createQuery(hql); // query.setString("name","张三"); // List<People> list = query.list(); // for (People people:list){ // System.out.println(people); // } // String hql1 = "from Customer where name = :name"; // Query query1 = session.createQuery(hql1); // query1.setString("name","张三"); // Customer customer = (Customer) query1.uniqueResult(); // String hql2 = "from Orders where customer = :customer"; // Query query2 = session.createQuery(hql2); // query2.setEntity("customer",customer); // List<Orders> list = query2.list(); // for(Orders orders:list){ // System.out.println(orders); // } session.close(); } } 结果：
4、模糊查询
查询名称包含
“四
”
的所有记录
“四
”
的所有记录
package com.southwind.test; import com.southwind.entity.People; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; import org.hibernate.query.Query; import java.util.List; public class Test11 { public static void main(String[] args) { //创建 Configuration Configuration configuration = new Configuration().configure(); //获取 SessionFactory SessionFactory sessionFactory = configuration.buildSessionFactory(); //获取 Session Session session = sessionFactory.openSession(); // String hql = "from People"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } // String hql = "from People"; // Query query = session.createQuery(hql); // query.setFirstResult(1);//设置起始下标 // query.setMaxResults(3);//设置截取⻓度 // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } // String hql = "from People where id = 4"; // Query query = session.createQuery(hql); // People people = (People) query.uniqueResult(); // System.out.println(people); String hql = "from People where name like '%四%'"; Query query = session.createQuery(hql); List<People> list = query.list(); for(People people:list){ System.out.println(people); } // String hql = "from People order by id asc "; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } // String hql = "select name from People where id = 6"; // Query query = session.createQuery(hql); // String name = (String) query.uniqueResult(); // System.out.println(name); // String hql = "from People where name = :name"; // Query query = session.createQuery(hql); // query.setString("name","张三"); // List<People> list = query.list(); // for (People people:list){ // System.out.println(people); // } // String hql1 = "from Customer where name = :name"; // Query query1 = session.createQuery(hql1); // query1.setString("name","张三"); // Customer customer = (Customer) query1.uniqueResult(); // String hql2 = "from Orders where customer = :customer"; // Query query2 = session.createQuery(hql2); // query2.setEntity("customer",customer); // List<Orders> list = query2.list(); // for(Orders orders:list){ // System.out.println(orders); // } session.close(); } } 结果：
5、order by
按照
id
进⾏降序排序
id
进⾏降序排序
package com.southwind.test; import com.southwind.entity.People; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; import org.hibernate.query.Query; import java.util.List; public class Test11 { public static void main(String[] args) { //创建 Configuration Configuration configuration = new Configuration().configure(); //获取 SessionFactory SessionFactory sessionFactory = configuration.buildSessionFactory(); //获取 Session Session session = sessionFactory.openSession(); // String hql = "from People"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } // String hql = "from People"; // Query query = session.createQuery(hql); // query.setFirstResult(1);//设置起始下标 // query.setMaxResults(3);//设置截取⻓度 // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } // String hql = "from People where id = 4"; // Query query = session.createQuery(hql); // People people = (People) query.uniqueResult(); // System.out.println(people); // String hql = "from People where name like '%四%'"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } String hql = "from People order by id desc "; Query query = session.createQuery(hql); List<People> list = query.list(); for(People people:list){ System.out.println(people); } // String hql = "select name from People where id = 6"; // Query query = session.createQuery(hql); // String name = (String) query.uniqueResult(); // System.out.println(name); // String hql = "from People where name = :name"; // Query query = session.createQuery(hql); // query.setString("name","张三"); // List<People> list = query.list(); // for (People people:list){ // System.out.println(people); // } // String hql1 = "from Customer where name = :name"; // Query query1 = session.createQuery(hql1); // query1.setString("name","张三"); // Customer customer = (Customer) query1.uniqueResult(); // String hql2 = "from Orders where customer = :customer"; // Query query2 = session.createQuery(hql2); // query2.setEntity("customer",customer); // List<Orders> list = query2.list(); // for(Orders orders:list){ // System.out.println(orders); // } session.close(); } } 结果：
6、查询实体对象的属性
package com.southwind.test; import com.southwind.entity.People; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; import org.hibernate.query.Query; import java.util.List; public class Test11 { public static void main(String[] args) { //创建 Configuration Configuration configuration = new Configuration().configure(); //获取 SessionFactory SessionFactory sessionFactory = configuration.buildSessionFactory(); //获取 Session Session session = sessionFactory.openSession(); //查询对象 // String hql = "from People"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //分⻚查询 // String hql = "from People"; // Query query = session.createQuery(hql); // query.setFirstResult(1);//设置起始下标 // query.setMaxResults(3);//设置截取⻓度 // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //where 条件查询 // String hql = "from People where id = 4"; // Query query = session.createQuery(hql); // People people = (People) query.uniqueResult(); // System.out.println(people); //模糊查询 // String hql = "from People where name like '%四%'"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //order by排序查询 // String hql = "from People order by id desc "; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //查询实体对象的属性，姓名 String hql = "select name from People where id = 6"; Query query = session.createQuery(hql); String name = (String) query.uniqueResult(); System.out.println(name); //占位符 // String hql = "from People where name = :name"; // Query query = session.createQuery(hql); // query.setString("name","张三"); // List<People> list = query.list(); // for (People people:list){ // System.out.println(people); // } //级联查询 // String hql1 = "from Customer where name = :name"; // Query query1 = session.createQuery(hql1); // query1.setString("name","张三"); // Customer customer = (Customer) query1.uniqueResult(); // String hql2 = "from Orders where customer = :customer"; // Query query2 = session.createQuery(hql2); // query2.setEntity("customer",customer); // List<Orders> list = query2.list(); // for(Orders orders:list){ // System.out.println(orders); // } session.close(); } } 结果：
7、占位符
package com.southwind.test; import com.southwind.entity.People; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; import org.hibernate.query.Query; import java.util.List; public class Test11 { public static void main(String[] args) { //创建 Configuration Configuration configuration = new Configuration().configure(); //获取 SessionFactory SessionFactory sessionFactory = configuration.buildSessionFactory(); //获取 Session Session session = sessionFactory.openSession(); //查询对象 // String hql = "from People"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //分⻚查询 // String hql = "from People"; // Query query = session.createQuery(hql); // query.setFirstResult(1);//设置起始下标 // query.setMaxResults(3);//设置截取⻓度 // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //where 条件查询 // String hql = "from People where id = 4"; // Query query = session.createQuery(hql); // People people = (People) query.uniqueResult(); // System.out.println(people); //模糊查询 // String hql = "from People where name like '%四%'"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //order by排序查询 // String hql = "from People order by id desc "; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //查询实体对象的属性，姓名 // String hql = "select name from People where id = 6"; // Query query = session.createQuery(hql); // String name = (String) query.uniqueResult(); // System.out.println(name); //占位符 String hql = "from People where name = :name"; Query query = session.createQuery(hql); query.setString("name","张三"); List<People> list = query.list(); for (People people:list){ System.out.println(people); } //级联查询 // String hql1 = "from Customer where name = :name"; // Query query1 = session.createQuery(hql1); // query1.setString("name","张三"); // Customer customer = (Customer) query1.uniqueResult(); // String hql2 = "from Orders where customer = :customer"; // Query query2 = session.createQuery(hql2); // query2.setEntity("customer",customer); // List<Orders> list = query2.list(); // for(Orders orders:list){ // System.out.println(orders); // } session.close(); } } 结果：
8、级联查询
package com.southwind.test; import com.southwind.entity.Customer; import com.southwind.entity.Orders; import com.southwind.entity.People; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; import org.hibernate.query.Query; import java.util.List; public class Test11 { public static void main(String[] args) { //创建 Configuration Configuration configuration = new Configuration().configure(); //获取 SessionFactory SessionFactory sessionFactory = configuration.buildSessionFactory(); //获取 Session Session session = sessionFactory.openSession(); //查询对象 // String hql = "from People"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //分⻚查询 // String hql = "from People"; // Query query = session.createQuery(hql); // query.setFirstResult(1);//设置起始下标 // query.setMaxResults(3);//设置截取⻓度 // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //where 条件查询 // String hql = "from People where id = 4"; // Query query = session.createQuery(hql); // People people = (People) query.uniqueResult(); // System.out.println(people); //模糊查询 // String hql = "from People where name like '%四%'"; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //order by排序查询 // String hql = "from People order by id desc "; // Query query = session.createQuery(hql); // List<People> list = query.list(); // for(People people:list){ // System.out.println(people); // } //查询实体对象的属性，姓名 // String hql = "select name from People where id = 6"; // Query query = session.createQuery(hql); // String name = (String) query.uniqueResult(); // System.out.println(name); //占位符 // String hql = "from People where name = :name"; // Query query = session.createQuery(hql); // query.setString("name","张三"); // List<People> list = query.list(); // for (People people:list){ // System.out.println(people); // } //级联查询 String hql1 = "from Customer where name = :name"; Query query1 = session.createQuery(hql1); query1.setString("name","张三"); Customer customer = (Customer) query1.uniqueResult(); String hql2 = "from Orders where customer = :customer"; Query query2 = session.createQuery(hql2); query2.setEntity("customer",customer); List<Orders> list = query2.list(); for(Orders orders:list){ System.out.println(orders); } session.close(); } } 结果：
今天的分享到此就结束了，感谢您的阅读，如果确实帮到您，您可以动动手指转发给其他人。
上一篇
已是最后文章
下一篇
已是最新文章
相关推荐
最新文章
