jap对单表的增删改查.zip

package test; import entity.User; import javax.persistence.*; import java.util.List; public class Test { // 增加 /* public static void main(String[] args) { //创建工厂 EntityManagerFactory entityManagerFactory= Persistence.createEntityManagerFactory("PZMYSQL"); //创建管理者对象 EntityManager manager=entityManagerFactory.createEntityManager(); //获取事务对象 EntityTransaction transaction=manager.getTransaction(); transaction.begin(); //增删改的方法 User user=new User(); user.setName("陈二"); //保存数据 manager.persist(user); //提交事务 transaction.commit(); //关闭资源 manager.close(); entityManagerFactory.close(); }*/ //删除 /* public static void main(String[] args) { //创建工厂 EntityManagerFactory entityManagerFactory= Persistence.createEntityManagerFactory("PZMYSQL"); //创建管理者对象 EntityManager manager=entityManagerFactory.createEntityManager(); //获取事务对象 EntityTransaction transaction=manager.getTransaction(); transaction.begin(); //增删改的方法 User user=new User(); user.setId(1); //删除数据 user=manager.find(User.class,1); manager.remove(user); //提交事务 transaction.commit(); //关闭资源 manager.close(); entityManagerFactory.close(); } */ // 修改 /* public static void main(String[] args) { //创建工厂 EntityManagerFactory entityManagerFactory= Persistence.createEntityManagerFactory("PZMYSQL"); //创建管理者对象 EntityManager manager=entityManagerFactory.createEntityManager(); //获取事务对象 EntityTransaction transaction=manager.getTransaction(); transaction.begin(); //增删改的方法 User user=new User(); //删除数据 user=manager.find(User.class,2); user.setName("王五"); manager.merge(user); //提交事务 transaction.commit(); //关闭资源 manager.close(); entityManagerFactory.close(); }*/ // ==========================基于写SQL，可以Mysql纯原生的sql，可以是基于对象的JPQL语句========================= // 查询全部基于createQuery(sql);基于JPQL 基于对象的查询 /* public static void main(String[] args) { //创建工厂 EntityManagerFactory entityManagerFactory= Persistence.createEntityManagerFactory("PZMYSQL"); //创建管理者对象 EntityManager manager=entityManagerFactory.createEntityManager(); //获取事务对象 EntityTransaction transaction=manager.getTransaction(); transaction.begin(); String sql="select user from User user"; Query query= manager.createQuery(sql); List<User> list=query.getResultList(); System.out.println(list.toString()); transaction.commit(); //关闭资源 manager.close(); entityManagerFactory.close(); }*/ //createNativeQuery基于原生的sql查询，需要指定查询的结果的类型 /*public static void main(String[] args) { //创建工厂 EntityManagerFactory entityManagerFactory= Persistence.createEntityManagerFactory("PZMYSQL"); //创建管理者对象 EntityManager manager=entityManagerFactory.createEntityManager(); //获取事务对象 EntityTransaction transaction=manager.getTransaction(); transaction.begin(); String sql="select * from user"; Query query= manager.createNativeQuery(sql,User.class); List<User> list=query.getResultList(); System.out.println(list.toString()); transaction.commit(); //关闭资源 manager.close(); entityManagerFactory.close(); }*/ // 基于createNamedQuery的查询，User中写的也是JPQL语句 /* public static void main(String[] args) { //创建工厂 EntityManagerFactory entityManagerFactory= Persistence.createEntityManagerFactory("PZMYSQL"); //创建管理者对象 EntityManager manager=entityManagerFactory.createEntityManager(); //获取事务对象 EntityTransaction transaction=manager.getTransaction(); transaction.begin(); Query query= manager.createNamedQuery("queryAll",User.class); List<User> list=query.getResultList(); System.out.println(list.toString()); transaction.commit(); //关闭资源 manager.close(); entityManagerFactory.close(); }*/ // =====================纯sql的增删改============================== // add 基于原生插入createNativeQuery，executeUpdate，需要指定返回的结果的类型 // https://betheme.net/houduan/1480.html?action=onClick /* public static void main(String[] args) { //创建工厂 EntityManagerFactory entityManagerFactory= Persistence.createEntityManagerFactory("PZMYSQL"); //创建管理者对象 EntityManager manager=entityManagerFactory.createEntityManager(); //获取事务对象 EntityTransaction transaction=manager.getTransaction(); transaction.begin(); Integer x= manager.createNativeQuery("insert into user(name) values ('张三')",Integer.class).executeUpdate(); System.out.println(x); transaction.commit(); //关闭资源 manager.close(); entityManagerFactory.close(); }*/ // 自己设置主键的值的话需要注释掉 @GeneratedValue(strategy = GenerationType.AUTO) public static void main(String[] args) { //创建工厂 EntityManagerFactory entityManagerFactory= Persistence.createEntityManagerFactory("PZMYSQL"); //创建管理者对象 EntityManager manager=entityManagerFactory.createEntityManager(); //获取事务对象 EntityTransaction transaction=manager.getTransaction(); transaction.begin(); User user=new User(); // user.setId(10); user.setName("赵六"); manager.persist(user); transaction.commit(); //关闭资源 manager.close(); entityManagerFactory.close(); } }