JavaWeb_(Hibernate框架)Hibernate中数据查询语句HQL基本用法

 

 

HQL(Hibernate Query Language) 是面向对象的查询语言, 它和 SQL 查询语言有些相似. 在 Hibernate 提供的各种检索方式中, HQL 是使用最广的一种检索方式.，HQL 查询包括以下步骤:

　　1、获取Hibernate Session对象

　　2、编写HQL语句

　　3、以HQL语句作为参数，调用Session的createQuery方法创建查询对象。

　　4、如果HQL语句包含参数，则调用Query的setXxx方法为参数赋值。

　　5、调用Query对象的list()或uniqueResult()方法返回查询结果列表（持久化实体集）

 

　　本文展示三种基本的HQL查询用法

　　1.1、基本查询 Query query = session.createQuery(hql);
　　2、条件查询
　　　　2.1、基本条件查询 ： String hql = "from com.Gary.domain.User where id = 1";
　　　　2.2、?占位符：String hql = "from com.Gary.domain.User where id = ?0";
　　　　　　　　　　　　query.setParameter(0, id);
　　　　2.3、命名占位符 ：String hql = "from com.Gary.domain.User where id = :id ";
　　　　　　　　　　　　query.setParameter("id", id);
　　3.1、分页查询
　　　　　　　　limit ?, ?
　　　　　　　　String hql = "from com.Gary.domain.User";
　　　　　　　　query.setFirstResult(1);
　　　　　　　　query.setMaxResults(1);

 

package com.Gary.dao;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.query.Query;

import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils;

public class HQLDao {

    //1.基本查询
    public void search()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        String hql = "from com.Gary.domain.User";
        
        Query query = session.createQuery(hql);
        List<User> list = query.list();        //查询多条数据
        //query.uniqueResult();    查询唯一的数据
        
        System.out.println(list);
        //模板：完成操作
        beginTransaction.commit();
        session.close();
        
        
    }
    
    
    //2.1基本条件查询
    public void search1()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = 1";
        Query query = session.createQuery(hql);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getName());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
    
    //2.2?占位符条件查询            id = 1
    public void search2(String id)
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = ?0";
        Query query = session.createQuery(hql);
        
        query.setParameter(0, id);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getUsername());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
    //2.3命名占位符条件查询            id = 1
    public void search3(String id)
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = :id";
        Query query = session.createQuery(hql);
        query.setParameter("id", id);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getUsername());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
    
    //3.1分页查询            
    public void search4()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user limit 0,1;
        String hql = "from com.Gary.domain.User";
        
        Query query = session.createQuery(hql);
        //设置一条数据为一页   访问第二页的数据
        query.setFirstResult(1);
        query.setMaxResults(1);
        
        List<User> list = query.list();
        
        System.out.println(list.get(0).getUsername());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
}

 

　　数据库user表　　

 

　　向数据库中添加假数据

　　

 

1.HQL基本查询语句

　　String hql = "from com.Gary.domain.User";
　　Query query = session.createQuery(hql);

 

　　HQLDao.java向数据库发起查询请求

//基本查询
    public void search()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        String hql = "from com.Gary.domain.User";
        
        Query query = session.createQuery(hql);
        List<User> list = query.list();        //查询多条数据
        //query.uniqueResult();    查询唯一的数据
        
        System.out.println(list);
        //模板：完成操作
        beginTransaction.commit();
        session.close();
        
        
    }

 

　　

package com.Gary.domain;

public class User {

    private String id;
    private String username;
    private String password;
    private String name;
    private String email;
    private String telephone;
    
    
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getTelephone() {
        return telephone;
    }
    public void setTelephone(String telephone) {
        this.telephone = telephone;
    }
    
    
    
}

 

package com.Gary.dao;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.query.Query;

import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils;

public class HQLDao {

    //基本查询
    public void search()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        String hql = "from com.Gary.domain.User";
        
        Query query = session.createQuery(hql);
        List<User> list = query.list();        //查询多条数据
        //query.uniqueResult();    查询唯一的数据
        
        System.out.println(list);
        //模板：完成操作
        beginTransaction.commit();
        session.close();
        
        
    }
    
}

 

 

2.1基本条件查询

　　String hql = "from com.Gary.domain.User where id = 1";
　　Query query = session.createQuery(hql);

 

　　HQLDao.java向数据库发起查询请求

//基本条件查询
    public void search1()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = 1";
        Query query = session.createQuery(hql);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getName());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }

 

　　

package com.Gary.domain;

public class User {

    private String id;
    private String username;
    private String password;
    private String name;
    private String email;
    private String telephone;
    
    
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getTelephone() {
        return telephone;
    }
    public void setTelephone(String telephone) {
        this.telephone = telephone;
    }
    
    
    
}

 

package com.Gary.domain;

public class User {

    private String id;
    private String username;
    private String password;
    private String name;
    private String email;
    private String telephone;
    
    
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getTelephone() {
        return telephone;
    }
    public void setTelephone(String telephone) {
        this.telephone = telephone;
    }
    
    
    
}

 

 

2.1?占位符条件查询

　　String hql = "from com.Gary.domain.User where id = ?0";
　　Query query = session.createQuery(hql);
        
　　query.setParameter(0, id);

 

　　HQLDao.java向数据库发起查询请求

//2.2?占位符条件查询            id = 1
    public void search2(String id)
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = ?0";
        Query query = session.createQuery(hql);
        
        query.setParameter(0, id);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getUsername());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }

 

　　

package com.Gary.domain;

public class User {

    private String id;
    private String username;
    private String password;
    private String name;
    private String email;
    private String telephone;
    
    
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getTelephone() {
        return telephone;
    }
    public void setTelephone(String telephone) {
        this.telephone = telephone;
    }
    
    
    
}

 

package com.Gary.dao;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.query.Query;

import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils;

public class HQLDao {

    //1.基本查询
    public void search()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        String hql = "from com.Gary.domain.User";
        
        Query query = session.createQuery(hql);
        List<User> list = query.list();        //查询多条数据
        //query.uniqueResult();    查询唯一的数据
        
        System.out.println(list);
        //模板：完成操作
        beginTransaction.commit();
        session.close();
        
        
    }
    
    
    //2.1基本条件查询
    public void search1()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = 1";
        Query query = session.createQuery(hql);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getName());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
    
    //2.2?占位符条件查询            id = 1
    public void search2(String id)
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = ?0";
        Query query = session.createQuery(hql);
        
        query.setParameter(0, id);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getUsername());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
    
}

 

 

2.3命名占位符

　　String hql = "from com.Gary.domain.User where id = :id";
　　Query query = session.createQuery(hql);
　　query.setParameter("id", id);

 

　　HQLDao.java向数据库发起查询请求

//2.3命名占位符条件查询            id = 1
    public void search3(String id)
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = :id";
        Query query = session.createQuery(hql);
        query.setParameter("id", id);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getUsername());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }

 

　　

package com.Gary.domain;

public class User {

    private String id;
    private String username;
    private String password;
    private String name;
    private String email;
    private String telephone;
    
    
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getTelephone() {
        return telephone;
    }
    public void setTelephone(String telephone) {
        this.telephone = telephone;
    }
    
    
    
}

 

package com.Gary.dao;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.query.Query;

import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils;

public class HQLDao {

    //1.基本查询
    public void search()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        String hql = "from com.Gary.domain.User";
        
        Query query = session.createQuery(hql);
        List<User> list = query.list();        //查询多条数据
        //query.uniqueResult();    查询唯一的数据
        
        System.out.println(list);
        //模板：完成操作
        beginTransaction.commit();
        session.close();
        
        
    }
    
    
    //2.1基本条件查询
    public void search1()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = 1";
        Query query = session.createQuery(hql);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getName());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
    
    //2.2?占位符条件查询            id = 1
    public void search2(String id)
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = ?0";
        Query query = session.createQuery(hql);
        
        query.setParameter(0, id);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getUsername());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
    //2.3命名占位符条件查询            id = 1
    public void search3(String id)
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = :id";
        Query query = session.createQuery(hql);
        query.setParameter("id", id);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getUsername());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
    
    
}

 

 

3.1分页查询

        //操作 select * from user limit 0,1;
        String hql = "from com.Gary.domain.User";
        
        Query query = session.createQuery(hql);

 

　　HQLDao.java向数据库发起查询请求

public void search4()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user limit 0,1;
        String hql = "from com.Gary.domain.User";
        
        Query query = session.createQuery(hql);
        //设置一条数据为一页   访问第二页的数据
        query.setFirstResult(1);
        query.setMaxResults(1);
        
        List<User> list = query.list();
        
        System.out.println(list.get(0).getUsername());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }

 

　　

package com.Gary.domain;

public class User {

    private String id;
    private String username;
    private String password;
    private String name;
    private String email;
    private String telephone;
    
    
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getTelephone() {
        return telephone;
    }
    public void setTelephone(String telephone) {
        this.telephone = telephone;
    }
    
    
    
}

 

package com.Gary.dao;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.query.Query;

import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils;

public class HQLDao {

    //1.基本查询
    public void search()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        String hql = "from com.Gary.domain.User";
        
        Query query = session.createQuery(hql);
        List<User> list = query.list();        //查询多条数据
        //query.uniqueResult();    查询唯一的数据
        
        System.out.println(list);
        //模板：完成操作
        beginTransaction.commit();
        session.close();
        
        
    }
    
    
    //2.1基本条件查询
    public void search1()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = 1";
        Query query = session.createQuery(hql);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getName());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
    
    //2.2?占位符条件查询            id = 1
    public void search2(String id)
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = ?0";
        Query query = session.createQuery(hql);
        
        query.setParameter(0, id);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getUsername());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
    //2.3命名占位符条件查询            id = 1
    public void search3(String id)
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user where id = 1;
        String hql = "from com.Gary.domain.User where id = :id";
        Query query = session.createQuery(hql);
        query.setParameter("id", id);
        User user = (User)query.uniqueResult();
        
        System.out.println(user.getUsername());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
    
    //3.1分页查询            
    public void search4()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //模板：开始HQL操作
        //HQL完全面对类    from类的全包名
        
        //操作 select * from user limit 0,1;
        String hql = "from com.Gary.domain.User";
        
        Query query = session.createQuery(hql);
        //设置一条数据为一页   访问第二页的数据
        query.setFirstResult(1);
        query.setMaxResults(1);
        
        List<User> list = query.list();
        
        System.out.println(list.get(0).getUsername());
        //模板：完成操作
        beginTransaction.commit();
        session.close();

    }
    
}