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(); } }
HQLDao.java
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;
}
}
User.java
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(); } }
HQLDao.java
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;
}
}
User.java
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;
}
}
HQLDao.java
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;
}
}
User.java
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(); } }
UserDao.java
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;
}
}
User.java
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(); } }
HQLDao.java
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;
}
}
User.java
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(); } }
HQLDao.java
JavaWeb_(Hibernate框架)Hibernate中数据查询语句HQL基本用法的更多相关文章
- JavaWeb_(Hibernate框架)Hibernate中数据查询语句Criteria基本用法
Criteria进行数据查询与HQL和SQL的区别是Criteria完全是面向对象的方式在进行数据查询,将不再看到有sql语句的痕迹,使用Criteria 查询数据包括以下步骤: 1. 通过sessi ...
- hibernate框架学习之数据查询（HQL）
lHibernate共提供5种查询方式 •OID数据查询方式 •HQL数据查询方式 •QBC数据查询方式 •本地SQL查询方式 •OGN数据查询方式 OID数据查询方式 l前提:已经获取到了对象的OI ...
- JavaWeb_(Hibernate框架)Hibernate中数据查询语句SQL基本用法
本文展示三种在Hibernate中使用SQL语句进行数据查询基本用法 1.基本查询 2.条件查询 3.分页查询 package com.Gary.dao; import java.util.List; ...
- hibernate框架学习之数据查询（HQL）helloworld
package cn.itcast.h3.hql; import java.util.List; import org.hibernate.Query; import org.hibernate.Se ...
- hibernate框架学习之数据查询（本地SQL）
本地SQL查询方式 lHibernate框架支持使用原生态SQL语句进行操作数据库 l查询对象SQLQuery由Session获取 •SQLQuery sq = s.createSQLQuery(&q ...
- hibernate框架学习之数据查询（QBC）
lQBC(Query By Criteria)是一种Hibernate中使用面向对象的格式进行查询的计数 lQBC查询方式步骤 •获取Session对象 •初始化Criteria对象(使用Sessio ...
- hibernate框架学习之数据查询（QBC）helloworld
package cn.itcast.h3.query.hql; import java.util.List; import org.hibernate.Criteria; import org.hib ...
- （数据科学学习手册28）SQL server 2012中的查询语句汇总
一.简介 数据库管理系统(DBMS)最重要的功能就是提供数据查询,即用户根据实际需求对数据进行筛选,并以特定形式进行显示.在Microsoft SQL Serve 2012 中,可以使用通用的SELE ...
- JavaWeb_(Struts2框架)Action中struts-default下result的各种转发类型
此系列博文基于同一个项目已上传至github 传送门 JavaWeb_(Struts2框架)Struts创建Action的三种方式 传送门 JavaWeb_(Struts2框架)struts.xml核 ...
随机推荐
- 基于bootstrap selectpicker ，实现select下拉框模糊查询功能
1.html代码块 需要引入bootstrap的css js jquery bootstrap.css bootstrap-select.min.css jquery-1.11.3.min.js bo ...
- 基于APM实现RPC服务和消息队列的指定消费
本文内容是基于公司现有框架整理的一篇专利文章.该框架包含完整的一套DevOps流程,包括工单系统(容器申请.服务部署等)\配置中心\路由配置中心\服务治理平台\消息治理平台\葛朗台(基于Docker+ ...
- Scala学习十四——模式匹配和样例类
一.本章要点 match表达式是更好的switch,不会有意外调入下一个分支 如果没有模式能够匹配,会抛出MatchError,可以用case _模式避免 模式可以包含一个随意定义的条件,称做守卫 你 ...
- Log4net采用外部配置文件和多记录器的方法
1) 创建配置文件,可以放在任意位置,名字可以任意的xml文件 例如,文件名 Log.Config.xml,内容如下 <?xml version="1.0" encoding ...
- Javascript中的事件二
<!------------------示例代码一---------------------><!DOCTYPE html PUBLIC "-//W3C//DTD XHTM ...
- luogu P3750 [六省联考2017]分手是祝愿
luogu loj 可以发现在最优策略中,每种操作最多只会做一次,并且操作的先后顺序并不会影响答案,所以考虑从后往前扫,碰到一个\(1\)就对这个位置\(i\)进行操作,这样的操作一定是最优策略.记最 ...
- java实现判定新旧版本号
废话不多说,直接上代码 /** * 判断是否为最新版本方法 将版本号根据.切分为int数组 比较 * * @param localVersion 本地版本号 * @param onlineVersio ...
- linux环境下安装python3的方法（转）
Linux 安装python3.7.0 我这里使用的时centos7-mini,centos系统本身默认安装有python2.x,版本x根据不同版本系统有所不同,可通过 python --V 或 ...
- LoadRunner（7）
一.参数化策略 1.Select next row(How? 如何取?)取值方式 选择下一行 1)Sequential:顺序的 每个VU都从第一行开始,顺序依次向下取值: 数据取完可以从头循环重复使用 ...
- jsp的标签库
Java Server Pages Standard Tag Libray(JSTL):JSP 标准标签库,是一个定制标签类库的集合,用于解决一些常见的问题,例如迭代一个映射或者集合.条件测试.XML ...