022——hibernate连接查询

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实体类及映射文件请参考015篇
测试类：
package test;import java.util.Iterator;import java.util.List;import junit.framework.TestCase;import org.hibernate.Session;import com.java.hibernate.HibernateUtils;public class JoinQueryTest extends TestCase{public void testQuery1() {Session session = null;try {session = HibernateUtils.getSession();session.beginTransaction();List students = session.createQuery("select c.name, s.name from Student s join s.classes c").list();for(Iterator iter = students.iterator(); iter.hasNext();) {Object[] obj = (Object[]) iter.next();System.out.println(obj[0] + "------" + obj[1]);}session.getTransaction().commit();} catch (Exception e) {e.printStackTrace();session.getTransaction().rollback();} finally {HibernateUtils.closeSession(session);}}public void testQuery2() {Session session = null;try {session = HibernateUtils.getSession();session.beginTransaction();List students = session.createQuery("select c.name, s.name from Student s left join s.classes c").list();for(Iterator iter = students.iterator(); iter.hasNext();) {Object[] obj = (Object[]) iter.next();System.out.println(obj[0] + "------" + obj[1]);}session.getTransaction().commit();} catch (Exception e) {e.printStackTrace();session.getTransaction().rollback();} finally {HibernateUtils.closeSession(session);}}public void testQuery3() {Session session = null;try {session = HibernateUtils.getSession();session.beginTransaction();List students = session.createQuery("select c.name, s.name from Student s right join s.classes c").list();for(Iterator iter = students.iterator(); iter.hasNext();) {Object[] obj = (Object[]) iter.next();System.out.println(obj[0] + "------" + obj[1]);}session.getTransaction().commit();} catch (Exception e) {e.printStackTrace();session.getTransaction().rollback();} finally {HibernateUtils.closeSession(session);}}}
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