1. 实验目的
通过修改实例，学习Mybatis的增删改查功能。2. 实验环境
项目管理：Maven 示例项目：MyBatisDemo IDE: Eclipse ，IDEA 数据库：MySql , H2, SQLite (三种选一种就可以)3. 实验要求
MyBatisDemo示例项目使用MyBatis对数据表country进行增删改查。请修改这一示例，使其对数据表 student进行增删改查。以压缩包的形式提交修改好的项目文件压缩包(文件命名规则为：学号+姓名.rar 或 zip )。4. 实验步骤
1. 首先在数据库中创建数据表student (id,studentID,studentName,studentClass)
2. 修改mybatis-config.xml中数据库的配置：
1 <properties resource="MySQL8.properties" />
3. 修改数据库配置文件：
driver=com.mysql.jdbc.Driver url=jdbc:mysql://localhost:3306/mysql useUnicode=true&characterEncoding=UTF-8 username=root password=123456
4.项目文件
mybatis配置：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--mybatis配置文件的标签顺序必须是以下顺序：
The content of element type “configuration”
must match “(properties?,settings?,typeAliases?,
typeHandlers?,objectFactory?,objectWrapperFactory?,
reflectorFactory?,plugins?,environments?,databaseIdProvider?,mappers?)”.
-->
<!-- <properties resource="H2Config.properties" /> -->
<properties resource="MySQL8.properties" />
<!-- <properties resource="SQLiteConfig.properties" /> -->
<settings>
<setting name="logImpl" value="LOG4J"/>
<setting name="cacheEnabled" value="true"/>
</settings>
<typeAliases>
<package name="cn.edu" />
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${driver}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<!-- <mapper resource="cn/edu/CountryMapper.xml"/> -->
<!-- 包下的所有映射器 -->
<package name="cn.edu" />
</mappers>
</configuration>
javabean：
package cn.edu;
public class Student {
private long id;
private int studentID;
private String studentName;
private String studentClass;
public Student() {
}
public Student(long id, int studentID, String studnetName, String studnetClass) {
this.id = id;
this.studentID = studentID;
this.studentName = studnetName;
this.studentClass = studnetClass;
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public int getStudentID() {
return studentID;
}
public void setStudentID(int studentID) {
this.studentID = studentID;
}
public String getStudentName() {
return studentName;
}
public void setStudentName(String studnetName) {
this.studentName = studnetName;
}
public String getStudentClass() {
return studentClass;
}
public void setStudentClass(String studnetClass) {
this.studentClass = studnetClass;
}
}
接口类：
package cn.edu;
import java.util.List;
public interface StudentMapper {
//查询所有记录,对应CountryMapper.xml中的id="selectAll"
public List<Student> selectAll();
//根据编号查询一条记录,对应CountryMapper.xml中的id="selectOne"
public Student selectOne(Long id);
//插入记录,对应CountryMapper.xml中的id="insertCountry"
public void insertStudent(Student student);
//更新记录,对应CountryMapper.xml中的id="updateCountry"
public void updateStudent(Student student);
//删除记录,对应CountryMapper.xml中的id="deleteCountry"
public void deleteStudent(Long id);
}
映射器xml：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.edu.StudentMapper">
<!-- 查询所有记录 -->
<select id="selectAll" resultType="Student" >
select id,studentID,studentName,studentClass from student
</select>
<!-- 根据编号查询一条记录 -->
<select id="selectOne" resultType="Student" parameterType="Long">
select id,studentID,studentName,studentClass from student where id=#{id}
</select>
<!-- 插入记录 -->
<insert id="insertStudent" >
insert into Student (id,studentID,studentName,studentClass)
values (#{id},#{studentID},#{studentName},#{studentClass})
</insert>
<!-- 更新记录 -->
<update id="updateStudent">
update Student set
id = #{id},
StudentID = #{studentID},
StudentName = #{studentName},
StudentClass=#{studentClass}
where id = #{id}
</update>
<!-- 删除记录 -->
<delete id="deleteStudent">
delete from Student where id = #{id}
</delete>
</mapper>
app：
package cn.edu;
import java.io.IOException;
import java.io.Reader;
import java.io.InputStream;
import java.util.List;
import java.util.Scanner;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
public class App {
public static void main(String[] args) throws Exception {
//读取配置文件，并创建Mybatis的SqlSessionFactory对象实例
InputStream reader = Resources.getResourceAsStream("mybatis-config.xml");
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
reader.close();
// 取得一个SqlSession实例
SqlSession sqlSession = sqlSessionFactory.openSession();
try {
// 取得CountryMapper映射器，映射器负责在数据表country与实体类Country之间建立对应关系
StudentMapper studentmapper = sqlSession.getMapper(StudentMapper.class);
//List<Country> countryList = sqlSession.selectList("selectAll");
// 查询country表中的所有记录
showAll(studentmapper);
// 显示country表中指定的记录
Scanner scanner = new Scanner(System.in);
System.out.print("请输入记录的ID号：");
Long id = scanner.nextLong();
Student student = (Student) studentmapper.selectOne(id);
System.out.println(
"test:" + student.getId() + " " + student.getStudentID() + " " + student.getStudentName()+" "+student.getStudentClass());
// 向country表中插入一条记录
System.out.print("增加一条新的记录，按照<编号,学号,姓名，班级>输入,以逗号分隔：");
String country_input = scanner.next();
System.out.println(country_input);
String[] country_list = country_input.split(",");
Student country_new = new Student();
country_new.setId(Long.parseLong(country_list[0]));
country_new.setStudentID(Integer.parseInt(country_list[1]));
country_new.setStudentClass(country_list[2]);
country_new.setStudentClass(country_list[3]);
studentmapper.insertStudent(country_new);
sqlSession.commit(); // 不要忘记提交
showAll(studentmapper);
//刪除一条记录
System.out.print("请输入删除记录的ID号：");
id = scanner.nextLong();
studentmapper.deleteStudent(id);
sqlSession.commit(); // 不要忘记提交
showAll(studentmapper);
//更新一条记录
System.out.print("请输入更新学生的ID号：");
id = scanner.nextLong();
System.out.print("请输入更新学生的学号：");
int ID = scanner.nextInt();
System.out.print("请输入新的学生名字：");
String name = scanner.next();
System.out.print("请输入新的学生班级：");
String code = scanner.next();
country_new.setId(id);
country_new.setStudentID(ID);
country_new.setStudentName(name);
country_new.setStudentClass(code);
studentmapper.updateStudent(country_new);;
sqlSession.commit(); // 不要忘记提交
showAll(studentmapper);
} finally {
sqlSession.close();
}
}
// 查询country表中的所有记录
private static void showAll(StudentMapper studentmapper) {
List<Student> studentList = studentmapper.selectAll();
System.out.println("id" + " 学号 " + " 姓名 "+" 班级");
for (Student student : studentList)
System.out.println(student.getId() + " "
+ student.getStudentID() + " "
+ student.getStudentName()+" "
+student.getStudentClass());
}
}
5. 运行方法：
mvn package cd target java -jar MyBatisDemo-1.0-SNAPSHOT.jar
6.运行截图
7.遇到的错误
1.
注意后面不能有空格。（非常坑）
2.拼写错误