hibernate query用法
阿新 • • 發佈:2019-02-20
package com.bjsxt.hibernate; import java.util.Date; import java.util.List; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.AnnotationConfiguration; import org.hibernate.tool.hbm2ddl.SchemaExport; import org.junit.AfterClass; import org.junit.BeforeClass; import org.junit.Test; public class HibernateQLTest { private static SessionFactory sf; @BeforeClass public static void beforeClass() { sf = new AnnotationConfiguration().configure().buildSessionFactory(); } @AfterClass public static void afterClass() { sf.close(); } @Test public void testSchemaExport() { new SchemaExport(new AnnotationConfiguration().configure()).create(false, true); } @Test public void testSave() { Session session = sf.openSession(); session.beginTransaction(); for(int i=0; i<10; i++) { Category c = new Category(); c.setName("c" + i); session.save(c); } for(int i=0; i<10; i++) { Category c = new Category(); c.setId(1); Topic t = new Topic(); t.setCategory(c); t.setTitle("t" + i); t.setCreateDate(new Date()); session.save(t); } for(int i=0; i<10; i++) { Topic t = new Topic(); t.setId(1); Msg m = new Msg(); m.setCont("m" + i); m.setTopic(t); session.save(m); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_01() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Category"); List<Category> categories = (List<Category>)q.list(); for(Category c : categories) { System.out.println(c.getName()); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_02() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Category c where c.name > 'c5'"); List<Category> categories = (List<Category>)q.list(); for(Category c : categories) { System.out.println(c.getName()); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_03() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Category c order by c.name desc"); List<Category> categories = (List<Category>)q.list(); for(Category c : categories) { System.out.println(c.getName()); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_04() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("select distinct c from Category c order by c.name desc"); List<Category> categories = (List<Category>)q.list(); for(Category c : categories) { System.out.println(c.getName()); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_05() { Session session = sf.openSession(); session.beginTransaction(); /*Query q = session.createQuery("from Category c where c.id > :min and c.id < :max"); //q.setParameter("min", 2); //q.setParameter("max", 8); q.setInteger("min", 2); q.setInteger("max", 8);*/ Query q = session.createQuery("from Category c where c.id > :min and c.id < :max") .setInteger("min", 2) .setInteger("max", 8); List<Category> categories = (List<Category>)q.list(); for(Category c : categories) { System.out.println(c.getId() + "-" + c.getName()); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_06() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Category c where c.id > ? and c.id < ?"); q.setParameter(0, 2) .setParameter(1, 8); // q.setParameter(1, 8); List<Category> categories = (List<Category>)q.list(); for(Category c : categories) { System.out.println(c.getId() + "-" + c.getName()); } session.getTransaction().commit(); session.close(); } //分頁 @Test public void testHQL_07() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Category c order by c.name desc"); q.setMaxResults(4); q.setFirstResult(2); List<Category> categories = (List<Category>)q.list(); for(Category c : categories) { System.out.println(c.getId() + "-" + c.getName()); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_08() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("select c.id, c.name from Category c order by c.name desc"); List<Object[]> categories = (List<Object[]>)q.list(); for(Object[] o : categories) { System.out.println(o[0] + "-" + o[1]); } session.getTransaction().commit(); session.close(); } //設定fetch type 為lazy後將不會有第二條sql語句 @Test public void testHQL_09() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Topic t where t.category.id = 1"); List<Topic> topics = (List<Topic>)q.list(); for(Topic t : topics) { System.out.println(t.getTitle()); //System.out.println(t.getCategory().getName()); } session.getTransaction().commit(); session.close(); } //設定fetch type 為lazy後將不會有第二條sql語句 @Test public void testHQL_10() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Topic t where t.category.id = 1"); List<Topic> topics = (List<Topic>)q.list(); for(Topic t : topics) { System.out.println(t.getTitle()); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_11() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Msg m where m.topic.category.id = 1"); for(Object o : q.list()) { Msg m = (Msg)o; System.out.println(m.getCont()); } session.getTransaction().commit(); session.close(); } //瞭解即可 //VO Value Object //DTO data transfer object @Test public void testHQL_12() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("select new com.bjsxt.hibernate.MsgInfo(m.id, m.cont, m.topic.title, m.topic.category.name) from Msg"); for(Object o : q.list()) { MsgInfo m = (MsgInfo)o; System.out.println(m.getCont()); } session.getTransaction().commit(); session.close(); } //動手測試left right join //為什麼不能直接寫Category名,而必須寫t.category //因為有可能存在多個成員變數(同一個類),需要指明用哪一個成員變數的連線條件來做連線 @Test public void testHQL_13() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("select t.title, c.name from Topic t join t.category c "); //join Category c for(Object o : q.list()) { Object[] m = (Object[])o; System.out.println(m[0] + "-" + m[1]); } session.getTransaction().commit(); session.close(); } //學習使用uniqueResult @Test public void testHQL_14() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Msg m where m = :MsgToSearch "); //不重要 Msg m = new Msg(); m.setId(1); q.setParameter("MsgToSearch", m); Msg mResult = (Msg)q.uniqueResult(); System.out.println(mResult.getCont()); session.getTransaction().commit(); session.close(); } @Test public void testHQL_15() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("select count(*) from Msg m"); long count = (Long)q.uniqueResult(); System.out.println(count); session.getTransaction().commit(); session.close(); } @Test public void testHQL_16() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("select max(m.id), min(m.id), avg(m.id), sum(m.id) from Msg m"); Object[] o = (Object[])q.uniqueResult(); System.out.println(o[0] + "-" + o[1] + "-" + o[2] + "-" + o[3]); session.getTransaction().commit(); session.close(); } @Test public void testHQL_17() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Msg m where m.id between 3 and 5"); for(Object o : q.list()) { Msg m = (Msg)o; System.out.println(m.getId() + "-" + m.getCont()); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_18() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Msg m where m.id in (3,4, 5)"); for(Object o : q.list()) { Msg m = (Msg)o; System.out.println(m.getId() + "-" + m.getCont()); } session.getTransaction().commit(); session.close(); } //is null 與 is not null @Test public void testHQL_19() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Msg m where m.cont is not null"); for(Object o : q.list()) { Msg m = (Msg)o; System.out.println(m.getId() + "-" + m.getCont()); } session.getTransaction().commit(); session.close(); } //is empty and is not empty @Test public void testHQL_20() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Topic t where t.msgs is empty"); for(Object o : q.list()) { Topic t = (Topic)o; System.out.println(t.getId() + "-" + t.getTitle()); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_21() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Topic t where t.title like '%5'"); for(Object o : q.list()) { Topic t = (Topic)o; System.out.println(t.getId() + "-" + t.getTitle()); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_22() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Topic t where t.title like '_5'"); for(Object o : q.list()) { Topic t = (Topic)o; System.out.println(t.getId() + "-" + t.getTitle()); } session.getTransaction().commit(); session.close(); } //不重要 @Test public void testHQL_23() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("select lower(t.title)," + "upper(t.title)," + "trim(t.title)," + "concat(t.title, '***')," + "length(t.title)" + " from Topic t "); for(Object o : q.list()) { Object[] arr = (Object[])o; System.out.println(arr[0] + "-" + arr[1] + "-" + arr[2] + "-" + arr[3] + "-" + arr[4] + "-"); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_24() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("select abs(t.id)," + "sqrt(t.id)," + "mod(t.id, 2)" + " from Topic t "); for(Object o : q.list()) { Object[] arr = (Object[])o; System.out.println(arr[0] + "-" + arr[1] + "-" + arr[2] ); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_25() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("select current_date, current_time, current_timestamp, t.id from Topic t"); for(Object o : q.list()) { Object[] arr = (Object[])o; System.out.println(arr[0] + " | " + arr[1] + " | " + arr[2] + " | " + arr[3]); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_26() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Topic t where t.createDate < :date"); q.setParameter("date", new Date()); for(Object o : q.list()) { Topic t = (Topic)o; System.out.println(t.getTitle()); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_27() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("select t.title, count(*) from Topic t group by t.title") ; for(Object o : q.list()) { Object[] arr = (Object[])o; System.out.println(arr[0] + "|" + arr[1]); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_28() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("select t.title, count(*) from Topic t group by t.title having count(*) >= 1") ; for(Object o : q.list()) { Object[] arr = (Object[])o; System.out.println(arr[0] + "|" + arr[1]); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_29() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Topic t where t.id < (select avg(t.id) from Topic t)") ; for(Object o : q.list()) { Topic t = (Topic)o; System.out.println(t.getTitle()); } session.getTransaction().commit(); session.close(); } @Test public void testHQL_30() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("from Topic t where t.id < ALL (select t.id from Topic t where mod(t.id, 2)= 0) ") ; for(Object o : q.list()) { Topic t = (Topic)o; System.out.println(t.getTitle()); } session.getTransaction().commit(); session.close(); } //用in 可以實現exists的功能 //但是exists執行效率高 @Test public void testHQL_31() { Session session = sf.openSession(); session.beginTransaction();// t.id not in (1) Query q = session.createQuery("from Topic t where not exists (select m.id from Msg m where m.topic.id=t.id)") ; // Query q = session.createQuery("from Topic t where exists (select m.id from Msg m where m.topic.id=t.id)") ; for(Object o : q.list()) { Topic t = (Topic)o; System.out.println(t.getTitle()); } session.getTransaction().commit(); session.close(); } //update and delete //規範並沒有說明是不是要更新persistent object,所以如果要使用,建議在單獨的trasaction中執行 @Test public void testHQL_32() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.createQuery("update Topic t set t.title = upper(t.title)") ; q.executeUpdate(); q = session.createQuery("from Topic"); for(Object o : q.list()) { Topic t = (Topic)o; System.out.println(t.getTitle()); } session.createQuery("update Topic t set t.title = lower(t.title)") .executeUpdate(); session.getTransaction().commit(); session.close(); } //不重要 @Test public void testHQL_33() { Session session = sf.openSession(); session.beginTransaction(); Query q = session.getNamedQuery("topic.selectCertainTopic"); q.setParameter("id", 5); Topic t = (Topic)q.uniqueResult(); System.out.println(t.getTitle()); session.getTransaction().commit(); session.close(); } //Native(瞭解) @Test public void testHQL_34() { Session session = sf.openSession(); session.beginTransaction(); SQLQuery q = session.createSQLQuery("select * from category limit 2,4").addEntity(Category.class); List<Category> categories = (List<Category>)q.list(); for(Category c : categories) { System.out.println(c.getName()); } session.getTransaction().commit(); session.close(); } }