Hibernate之QBC检索和本地SQL检索

QBC查询就是通过使用Hibernate提供的Query By Criteria API来查询对象，这种API封装了SQL语句的动态拼装，对查询提供了更加面向对象的功能接口

本地SQL查询来完善HQL不能涵盖所有的查询特性。

====================代码区======================

测试类

  1 package com.yl.hibernate.test;
  2
  3
  4 import java.util.ArrayList;
  5 import java.util.Arrays;
  6 import java.util.LinkedHashSet;
  7 import java.util.List;
  8 import java.util.Set;
  9
 10 import oracle.net.aso.e;
 11
 12 import org.hibernate.Criteria;
 13 import org.hibernate.Query;
 14 import org.hibernate.Session;
 15 import org.hibernate.SessionFactory;
 16 import org.hibernate.Transaction;
 17 import org.hibernate.cfg.Configuration;
 18 import org.hibernate.criterion.Conjunction;
 19 import org.hibernate.criterion.Disjunction;
 20 import org.hibernate.criterion.MatchMode;
 21 import org.hibernate.criterion.Order;
 22 import org.hibernate.criterion.Projection;
 23 import org.hibernate.criterion.Projections;
 24 import org.hibernate.criterion.Restrictions;
 25 import org.hibernate.service.ServiceRegistry;
 26 import org.hibernate.service.ServiceRegistryBuilder;
 27 import org.junit.After;
 28 import org.junit.Before;
 29 import org.junit.Test;
 30
 31 import com.yl.hibernate.entities.Department;
 32 import com.yl.hibernate.entities.Employee;
 33
 34 public class HibernateTest {
 35
 36     private SessionFactory sessionFactory;
 37     private Session session;
 38     private Transaction transaction;
 39
 40     @Before
 41     public void init() {
 42         Configuration configuration = new Configuration().configure();
 43         ServiceRegistry serviceRegistry =
 44                 new ServiceRegistryBuilder().applySettings(configuration.getProperties())
 45                                             .buildServiceRegistry();
 46
 47         sessionFactory = configuration.buildSessionFactory(serviceRegistry);
 48
 49         session = sessionFactory.openSession();
 50
 51         transaction = session.beginTransaction();
 52     }
 53     @After
 54     public void destory() {
 55         transaction.commit();
 56
 57         session.close();
 58
 59         sessionFactory.close();
 60     }
 61
 62
 63     @Test
 64     public void testQBC() {
 65         //1.创建一个Ctiteria对象
 66         Criteria criteria = session.createCriteria(Employee.class);
 67         //2.添加查询条件:在QBC中查询条件使用Criterion来表示
 68         //Criterion可以通过Restrictions 的静态方法得到
 69         criteria.add(Restrictions.eq("email", "PRESIDENT"));
 70         criteria.add(Restrictions.gt("salary", 500f));
 71         //3.执行查询
 72         Employee employee = (Employee) criteria.uniqueResult();
 73         System.out.println(employee);
 74     }
 75
 76     @Test
 77     public void testQBC2() {
 78
 79         Criteria criteria = session.createCriteria(Employee.class);
 80         //1.AND: 使用Conjunction表示
 81         //Conjunction 本身就是一个Criterion对象
 82         //且其中还可以添加Criterion对象
 83         Conjunction conjunction = Restrictions.conjunction();
 84         conjunction.add(Restrictions.like("name", "A", MatchMode.ANYWHERE));
 85         Department dept = new Department();
 86         dept.setId(20);
 87         conjunction.add(Restrictions.eq("dept", dept));
 88         System.out.println(conjunction);
 89
 90         //2. OR
 91         Disjunction disjunction = Restrictions.disjunction();
 92         disjunction.add(Restrictions.ge("salary", 1000F));
 93         disjunction.add(Restrictions.isNotNull("email"));
 94
 95         criteria.add(disjunction);
 96         criteria.add(conjunction);
 97
 98         criteria.list();
 99         /**
100          *  where
101         (
102             this_.SALARY>=?
103             or this_.EMAIL is not null
104         )
105         and (
106             this_.NAME like ?
107             and this_.DEPT_ID=?
108         )
109          */
110     }
111
112     @Test
113     public void testQBC3() {
114         Criteria criteria = session.createCriteria(Employee.class);
115
116         //统计查询： 使用Projection表示: 可以由Projections的静态方法得到
117         criteria.setProjection(Projections.max("salary"));
118
119         System.out.println(criteria.uniqueResult());
120     }
121
122     @Test
123     public void testQBC4() {
124         Criteria criteria = session.createCriteria(Employee.class);
125
126         //1.添加排序
127         criteria.addOrder(Order.asc("salary"));
128         criteria.addOrder(Order.desc("email"));
129
130         //2.添加分页
131         int pageSize = 3;
132         int pageNo = 2;
133         criteria.setFirstResult((pageNo - 1) * pageSize)
134                 .setMaxResults(pageSize)
135                 .list();
136
137     }
138
139     @Test
140     public void testNative() {
141         String sql = "INSERT INTO YL_department VALUES(?, ?)";
142         Query query = session.createSQLQuery(sql);
143
144         query.setInteger(0, 50)
145              .setString(1, "DEV")
146              .executeUpdate();
147     }
148
149     @Test
150     public void testHQLUpdate() {
151         String hql = "DELETE FROM Department d WHERE d.id = :id";
152
153         session.createQuery(hql).setInteger("id", 50)
154                                 .executeUpdate();
155
156     }
157 }