mybatis学习笔记2Word格式.docx
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mybatis学习笔记2Word格式.docx
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111'
insertintostudents(id,name,cid)values(1,'
哈哈'
1);
3)创建Students.java和Card.java
publicclassCard{
privateIntegerid;
privateStringnum;
privateStudentstudent;
publicCard(){}
publicIntegergetId(){
returnid;
}
publicvoidsetId(Integerid){
this.id=id;
publicStringgetNum(){
returnnum;
publicvoidsetNum(Stringnum){
this.num=num;
publicStudentgetStudent(){
returnstudent;
publicvoidsetStudent(Studentstudent){
this.student=student;
}
publicclassStudent{
privateStringname;
privateCardcard;
publicStudent(){}
publicStringgetName(){
returnname;
publicvoidsetName(Stringname){
this.name=name;
publicCardgetCard(){
returncard;
publicvoidsetCard(Cardcard){
this.card=card;
4)创建StudentMapper.xml和CardMapper.xml
CardMapper.xml
?
xmlversion="
1.0"
encoding="
UTF-8"
?
!
DOCTYPEmapperPUBLIC"
-//mybatis.org//DTDMapper3.0//EN"
"
http:
//mybatis.org/dtd/mybatis-3-mapper.dtd"
mappernamespace="
cardNamespace"
<
resultMaptype="
cn.itcast.javaee.mybatis.one2one.Card"
id="
cardMap"
<
idproperty="
id"
column="
/>
resultproperty="
num"
/resultMap>
/mapper>
StudentMapper.xml
studentNamespace"
cn.itcast.javaee.mybatis.one2one.Student"
studentMap"
name"
/>
associationproperty="
card"
resultMap="
cardNamespace.cardMap"
selectid="
findById"
parameterType="
int"
selects.id,s.name,c.id,c.num
fromstudentssinnerjoincardsc
ons.cid=c.id
ands.id=#{id}
/select>
5)创建StudentCardDao.java
publicclassStudentCardDao{
/**
*查询1号【学生】
*/
publicStudentfindById(intid)throwsException{
SqlSessionsqlSession=null;
try{
sqlSession=MybatisUtil.getSqlSession();
returnsqlSession.selectOne("
studentNamespace.findById"
id);
}catch(Exceptione){
e.printStackTrace();
throwe;
}finally{
MybatisUtil.closeSqlSession();
}
publicstaticvoidmain(String[]args)throwsException{
StudentCardDaodao=newStudentCardDao();
Studentstudent=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】
一对多图示.JPG>
2)创建grades.sql和students.sql
droptablegrades;
createtablegrades(
gidint(5)primarykey,
gnamevarchar(10)
);
sidint(5)primarykey,
snamevarchar(10),
sgidint(5),
constraintsgid_fkforeignkey(sgid)referencesgrades(gid)
insertintogrades(gid,gname)values(1,'
java'
insertintostudents(sid,sname,sgid)values(1,'
insertintostudents(sid,sname,sgid)values(2,'
呵呵'
3)创建Grade.java和Student.sql
/**
*班级(单方)
*@authorAdminTC
publicclassGrade{
privateList<
Student>
studentList=newArrayList<
();
publicGrade(){}
publicList<
getStudentList(){
returnstudentList;
publicvoidsetStudentList(List<
studentList){
this.studentList=studentList;
*学生(多方)
privateGradegrade;
publicGradegetGrade(){
returngrade;
publicvoidsetGrade(Gradegrade){
this.grade=grade;
4)创建GradeMapper.xml和StudentMapper.xml
GradeMapper.xml
gradeNamespace"
cn.itcast.javaee.mybatis.one2many.Grade"
gradeMap"
gid"
gname"
collectionproperty="
studentList"
studentNamespace.studentMap"
findGradeByName"
string"
selectg.gid,g.gname,s.sid,s.sname
fromgradesg,studentss
whereg.gid=s.sgid
ands.sname=#{name}
cn.itcast.javaee.mybatis.one2many.Student"
sid"
sname"
grade"
gradeNamespace.gradeMap"
findAllByName"
selects.sid,s.sname,g.gid,g.gname
andg.gname=#{name}
5)创建GradeStudentDao.java
publicclassGradeStudentDao{
*查询java班级有哪些【学生】
findAllByName(Stringname)throwsException{
returnsqlSession.selectList("
studentNamespace.findAllByName"
name);
*查询哈哈属于哪个【班级】
publicGradefindGradeByName(Stringname)throwsException{
gradeNamespace.findGradeByName"
GradeStudentDaodao=newGradeStudentDao();
List<
studentList=dao.findAllByName("
java"
for(Students:
studentList){
System.out.println(s.getId()+"
+s.getName()+"
+s.getGrade().getId()+"
+s.getGrade().getName());
Gradegrade=dao.findGradeByName("
哈哈"
System.out.println(grade.getId()+"
+grade.getName());
第二十章mybatis多对多映射【学生与课程】
多对多图示.JPG>
2)创建students.sql和courses.sql和middles.sql
droptablemiddles;
droptablecourses;
snamevarchar(10)
createtablecourses(
cidint(5)primarykey,
cnamevarchar(10)
createtablemiddles(
sidint(5),
primarykey(sid,cid)
insertintostudents(sid,sname)values(1,'
insertintostudents(sid,sname)values(2,'
insertintocourses(cid,cname)values(1,'
insertintocourses(cid,cname)values(2,'
net'
insertintomiddles(sid,cid)values(1,1);
insertintomiddles(sid,cid)values(1,2);
insertintomiddles(sid,cid)values(2,1);
insertintomiddles(sid,cid)values(2,2);
select*fromstudents;
select*fromcourses;
select*frommiddles;
3)创建Student.java和Course.java
Course>
courseList=newArrayList<
getCourseList(){
returncourseList;
publicvoidsetCourseList(List<
courseList){
this.courseList=courseList;
*课程(多方)
publicclassCourse{
publicCourse(){}
4)创建StudentMapper.xml和CourseMapper.xml
cn.itcast.javaee.mybatis.many2many.Student"
findStudentByName"
selects.sid,s.sname
fromstudentss,middlesm,coursesc
wheres.sid=m.sid
andm.cid=c
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