J2EE应用持久化和Hibernate(三).ppt

第六讲 数据库连接和Hibernate （三）Hibernate开发实例,内容安排,MyEclipse 开发Hibernate过程 三种映射关系实例,MyEclipse 开发Hibernate过程,创建Web/JAVA 工程 增加Hibernate功能 MyEclipse-Add Hibernate Capabilities,确定数据库连接细节 需要实现创建DB Driver Window-Show View-Other-DB Browser,生成Hibernate.cfg.xml,Hibernate反向工程,生成映射文件和类文件,Addr.hbm.xml AbstractAddr.java Addr.java AddrDAO.java,一对一关联,Userinfo表结构,create table USERINFO ( USERID VARCHAR2(20) not null, USERNAME VARCHAR2(20), AGE VARCHAR2(20), ADDRID VARCHAR2(20), PRIMARY KEY (USERID ), CONSTRAINT addrid FOREIGN KEY (ADDRID) REFERENCES addr (ADDRID) ),Addr表结构,create table ADDR ( ADDRID VARCHAR2(20) not null, LOCATION VARCHAR2(20), POSTCODE VARCHAR2(20), PRIMARY KEY (ADDRID) ),Addr POJO,public class Addr implements java.io.Serializable / Fields private String addrid; private String location; private String postcode; ,Addr映射描述,Userinfo POJO,public class Userinfo implements java.io.Serializable / Fields private String userid; private Addr addr; private String username; private String age; ,Userinfo映射文件描述,关联查询,Session session = HibernateSessionFactory.getSession(); Userinfo u = (Userinfo)session.load(Userinfo.class,“1001“); System.out.println(u.getUsername(); System.out.println(u.getAddr().getLocation(); HibernateSessionFactory.closeSession();,关联保存,Userinfo u = new Userinfo(); u.setUserid(“1002“); u.setUsername(“JONES“); u.setAge(“26“); /级联保存addr的信息，而不再需要单独save方法，hibernate会自动save addr的信息 Addr addr = new Addr(); addr.setAddrid(“SHANGHAI002“); addr.setLocation(“BAOSHANLU“); addr.setPostcode(“200852“); u.setAddr(addr); Transaction t = session.beginTransaction(); session.save(u); mit();,多对一关联,多对一表结构,create table EMPLOYEE ( EMPID VARCHAR2(50) not null, ENAME VARCHAR2(20), SAL VARCHAR2(20), JOB VARCHAR2(20), DEPTID VARCHAR2(20) ); create table DEPARTMENT ( DEPTID VARCHAR2(50) not null, DNAME VARCHAR2(20), LOCATION VARCHAR2(20) );,Department.hbm.xml, 或: ,Department.java,private String deptid; private String dname; private String location; private Set emps; public Set getEmps() return emps; public void setEmps(Set emps) this.emps = emps; ,Employee.hbm.xml, 或 ,Employee.java,private String empid; private String ename; private String sal; private String job; private Department dept; public Department getDept() return dept; public void setDept(Department dept) this.dept = dept; ,级联保存,Session s = HibernateSessionFactory.getSession(); Department d = new Department(); d.setDeptid(“1001“); d.setDname(“R,级联删除,Session s = HibernateSessionFactory.getSession(); Department d = new Department(); d.setDeptid(“1001“); Set emps = new HashSet(); Employee e1 = new Employee(“7001“); Employee e2 = new Employee(“7002“); Employee e3 = new Employee(“7003“); emps.add(e1); emps.add(e2); emps.add(e3); d.setEmps(emps); Transaction t = s.beginTransaction(); s.delete(d); mit(); HibernateSessionFactory.closeSession();,级联查询,Session s = HibernateSessionFactory.getSession(); Query q = s.createQuery(“select e from Employee e where e.empid=7001“); List list = q.list(); for(int i=0;ilist.size();i+) Employee e = (Employee)list.get(i); Department d = e.getDept(); System.out.println(d.getDname(); HibernateSessionFactory.closeSession();,多对多关联,多对多表结构,create table COURSE ( COURID VARCHAR2(50) not null primary key, COURNAME VARCHAR2(20) ); create table STUDENT ( STUID VARCHAR2(50) not null primary key, STUNAME VARCHAR2(20) ); create table STUCOUR ( STUID VARCHAR2(50) not null, COURID VARCHAR2(50) not null );,Student.java,private String stuid; private String stuname; private Set cours;,Course.java,private String courid; private String courname; private Set stus;,Stucour.java,private StucourId id;,主键类StucourId,private String stuid; private String courid;,Student.xml,Course.hbm.xml,级联保存,Session s = HibernateSessionFactory.getSession(); Student stu = new Student(); stu.setStuid(“1002“); stu.setStuname(“zhangshan“); Set cours = new HashSet(); Course c1 = new Course(“9001“,“English“); Course c2 = new Course(“9002“,“phylisc“); cours.add(c1); cours.add(c2); stu.setCours(cours); Transaction t = s.beginTransaction(); s.save(stu); mit(); HibernateSessionFactory.closeSession();,级联查询,Session s = HibernateSessionFactory.getSession(); Student stu = new Student(); stu = (Student)s.get(Student.class, “1001“); System.out.println(stu.getStuid()+“:“+stu.getStuname(); Set cours = stu.getCours(); Iterator it = cours.iterator(); while(it.hasNext() Course c = (Course)it.next(); System.out.println(c.getCourname(); HibernateSessionFactory.closeSession();,删除学生,Session s = HibernateSessionFactory.getSession(); Student stu = new Student(); stu.setStuid(“1001“); Transaction t = s.beginTransaction(); s.delete(stu); mit(); HibernateSessionFactory.closeSession(); 自动删除关联表中的信息,删除学生及关联课程,在删除学生信息的同时，删除关联课程信息 Session s = HibernateSessionFactory.getSession(); Student stu = new Student(); stu.setStuid(“1001“); Set cours = new HashSet(); Course c1 = new Course(“9001“); Course c2 = new Course(“9002“); cours.add(c1); cours.add(c2); stu.setCours(cours); Transaction t = s.beginTransaction(); s.delete(stu); mit(); HibernateSessionFactory.closeSession();,删除学生及关联课程,删除学生信息，同时查询该学生对应的所有课程信息，一并删除 Session s = HibernateSessionFactory.getSession(); Student stu = new Student(); stu.setStuid(“1001“); Query q = s.createQuery(“select c from Course c,Stucour sc “ + “wh