mybatis学习笔记2.doc

《mybatis学习笔记2.doc》由会员分享，可在线阅读，更多相关《mybatis学习笔记2.doc（19页珍藏版）》请在淘文阁 - 分享文档赚钱的网站上搜索。

1、如有侵权，请联系网站删除，仅供学习与交流mybatis学习笔记2【精品文档】第 19 页第十六章 回顾SQL99中的连接查询 1）内连接 2）外连接 3）自连接 第十七章 回顾hibernate多表开发1）一对一2）一对多3）多对多第十八章 mybatis一对一映射【学生与身份证】1）参见2）创建students.sql和cards.sql drop table students;drop table cards;create table cards(idint(5)primary key,num varchar(20);create table students(idint(5)primar

2、y key,name varchar(10),cid int(5),constraint cid_fk foreign key(cid) references cards(id);insert into cards(id,num) values(1,111);insert into students(id,name,cid) values(1,哈哈,1);3）创建Students.java和Card.java public class Card private Integer id;private String num;private Student student;public Card()

3、public Integer getId() return id;public void setId(Integer id) this.id = id;public String getNum() return num;public void setNum(String num) this.num = num;public Student getStudent() return student;public void setStudent(Student student) this.student = student;public class Student private Integer i

4、d;private String name;private Card card;public Student()public Integer getId() return id;public void setId(Integer id) this.id = id;public String getName() return name;public void setName(String name) this.name = name;public Card getCard() return card;public void setCard(Card card) this.card = card;

5、4）创建StudentMapper.xml和CardMapper.xml CardMapper.xml StudentMapper.xmlselect s.id,s.name,c.id,c.numfrom students s inner join cards con s.cid = c.id and s.id = #id5）创建StudentCardDao.java public class StudentCardDao /* * 查询1号【学生】 */public Student findById(int id) throws ExceptionSqlSession sqlSession

6、= null;trysqlSession = MybatisUtil.getSqlSession();return sqlSession.selectOne(studentNamespace.findById,id);catch(Exception e)e.printStackTrace();throw e;finallyMybatisUtil.closeSqlSession();public static void main(String args) throws ExceptionStudentCardDao dao = new StudentCardDao();Student stude

7、nt = dao.findById(1);System.out.println(student.getId()+:+student.getName();System.out.println(student.getCard().getId()+:+student.getCard().getNum();第十九章 mybatis一对多映射【班级与学生】1）参见2）创建grades.sql和students.sqldrop table students;drop table grades;create table grades(gidint(5)primary key,gname varchar(10

8、) );create table students(sidint(5)primary key,sname varchar(10), sgid int(5), constraint sgid_fk foreign key(sgid) references grades(gid);insert into grades(gid,gname) values(1,java);insert into students(sid,sname,sgid) values(1,哈哈,1);insert into students(sid,sname,sgid) values(2,呵呵,1);3）创建Grade.ja

9、va和Student.sql/* * 班级（单方） * author AdminTC */public class Grade private Integer id;private String name;private List studentList = new ArrayList();public Grade()public Integer getId() return id;public void setId(Integer id) this.id = id;public String getName() return name;public void setName(String n

10、ame) this.name = name;public List getStudentList() return studentList;public void setStudentList(List studentList) this.studentList = studentList;/* * 学生（多方） * author AdminTC */public class Student private Integer id;private String name;private Grade grade;public Student()public Integer getId() retu

11、rn id;public void setId(Integer id) this.id = id;public String getName() return name;public void setName(String name) this.name = name;public Grade getGrade() return grade;public void setGrade(Grade grade) this.grade = grade;4）创建GradeMapper.xml和StudentMapper.xml GradeMapper.xmlselect g.gid,g.gname,s

12、.sid,s.snamefrom grades g,students swhere g.gid = s.sgidand s.sname = #name StudentMapper.xmlselect s.sid,s.sname,g.gid,g.gnamefrom grades g,students swhere g.gid = s.sgidand g.gname = #name5）创建GradeStudentDao.javapublic class GradeStudentDao /* * 查询java班级有哪些【学生】 */public List findAllByName(String n

13、ame) throws ExceptionSqlSession sqlSession = null;trysqlSession = MybatisUtil.getSqlSession();return sqlSession.selectList(studentNamespace.findAllByName,name);catch(Exception e)e.printStackTrace();throw e;finallyMybatisUtil.closeSqlSession();/* * 查询哈哈属于哪个【班级】 */public Grade findGradeByName(String n

14、ame) throws ExceptionSqlSession sqlSession = null;trysqlSession = MybatisUtil.getSqlSession();return sqlSession.selectOne(gradeNamespace.findGradeByName,name);catch(Exception e)e.printStackTrace();throw e;finallyMybatisUtil.closeSqlSession();public static void main(String args) throws ExceptionGrade

15、StudentDao dao = new GradeStudentDao();List studentList = dao.findAllByName(java);for(Student s : studentList)System.out.println(s.getId()+:+s.getName()+:+s.getGrade().getId()+:+s.getGrade().getName();Grade grade = dao.findGradeByName(哈哈);System.out.println(grade.getId()+:+grade.getName();第二十章 mybat

16、is多对多映射【学生与课程】1）参见2）创建students.sql和courses.sql和middles.sqldrop table middles;drop table students;drop table courses;create table students(sid int(5) primary key,sname varchar(10);create table courses(cid int(5) primary key,cname varchar(10);create table middles(sid int(5),cid int(5),primary key(sid,

17、cid);insert into students(sid,sname) values(1,哈哈);insert into students(sid,sname) values(2,呵呵);insert into courses(cid,cname) values(1,java);insert into courses(cid,cname) values(2,net);insert into middles(sid,cid) values(1,1);insert into middles(sid,cid) values(1,2);insert into middles(sid,cid) val

18、ues(2,1);insert into middles(sid,cid) values(2,2);select * from students;select * from courses;select * from middles;3）创建Student.java和Course.java/* * 学生(多方) * author AdminTC */public class Student private Integer id;private String name;private List courseList = new ArrayList();public Student()public

19、 Integer getId() return id;public void setId(Integer id) this.id = id;public String getName() return name;public void setName(String name) this.name = name;public List getCourseList() return courseList;public void setCourseList(List courseList) this.courseList = courseList;/* * 课程(多方) * author Admin

20、TC */public class Course private Integer id;private String name;private List studentList = new ArrayList();public Course()public Integer getId() return id;public void setId(Integer id) this.id = id;public String getName() return name;public void setName(String name) this.name = name;public List getS

21、tudentList() return studentList;public void setStudentList(List studentList) this.studentList = studentList;4）创建StudentMapper.xml和CourseMapper.xml StudentMapper.xmlselect s.sid,s.snamefrom students s,middles m,courses cwhere s.sid = m.sid and m.cid = c.cidand ame = #name CourseMapper.xmlselect c.cid

22、,amefrom students s,middles m,courses cwhere s.sid = m.sid and m.cid = c.cidand s.sname = #name5）创建students.sql和courses.sql和middles.sqlpublic class StudentCourseDao /* * 查询哈哈选学的【课程】 */public List findCourseByName(String name) throws ExceptionSqlSession sqlSession = null;trysqlSession = MybatisUtil.g

23、etSqlSession();return sqlSession.selectList(courseNamespace.findCourseByName,name);catch(Exception e)e.printStackTrace();throw e;finallyMybatisUtil.closeSqlSession();/* * 查询java课程有哪些【学生】 */public List findStudentByName(String name) throws ExceptionSqlSession sqlSession = null;trysqlSession = Mybatis

24、Util.getSqlSession();return sqlSession.selectList(studentNamespace.findStudentByName,name);catch(Exception e)e.printStackTrace();throw e;finallyMybatisUtil.closeSqlSession();public static void main(String args) throws ExceptionStudentCourseDao dao = new StudentCourseDao();/List courseList = dao.find

25、CourseByName(哈哈);/for(Course c : courseList)/System.out.println(c.getId()+:+c.getName();/List studentList = dao.findStudentByName(java);for(Student s : studentList)System.out.println(s.getId()+:+s.getName(); 第二十一章 spring + mybatis + mysql/oracle开发1）创建一个spring-mybatis-mysql这么一个javaweb或java工程2）导入sprin

26、g-ioc，spring-aop，spring-transaction，mybatis，c3p0，mysql/oracle相关的jar包和spring整合mybatis的jar包3）创建students.sql-mysqlcreate table students( sid int(5) primary key, sname varchar(10), ssal double(8,2);4）创建Student.java/* * 学生 * author AdminTC */public class Student private Integer id;/编号private String name;

27、/姓名private Double sal;/薪水public Student()public Student(Integer id, String name, Double sal) this.id = id;this.name = name;this.sal = sal;public Integer getId() return id;public void setId(Integer id) this.id = id;public String getName() return name;public void setName(String name) this.name = name;

28、public Double getSal() return sal;public void setSal(Double sal) this.sal = sal;5）创建StudentMapper.xmlinsert into students(sid,sname,ssal) values(#id,#name,#sal)6）创建StudentDao.javapublic class StudentDao private SqlSessionFactory sqlSessionFactory;public void setSqlSessionFactory(SqlSessionFactory sq

29、lSessionFactory) this.sqlSessionFactory = sqlSessionFactory;public void insert(Student student)SqlSession sqlSession = sqlSessionFactory.openSession();sqlSession.insert(studentNamespace.insert,student);/int i = 10/0;public static void main(String args) ApplicationContext ac = new ClassPathXmlApplica

30、tionContext(new Stringspring.xml);StudentDao studentDao = (StudentDao) ac.getBean(studentDaoID);studentDao.insert(new Student(1,哈哈,7000D);7）在src目录下创建mybatis.xml8）在src目录下创建spring.xml beans xmlns=http:/www.springframework.org/schema/beans xmlns:xsi=http:/www.w3.org/2001/XMLSchema-instance xmlns:context=http:/www.springframework.org/schema/context xmlns:aop=http:/www.springframework.org/schema/aop xmlns:tx=http:/www.springframework.org/schema/tx xmlns:mvc=http:/www.springframework.org/schema/mvc xsi:schemaLocation= http:/www.springframework.org/sc