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MyBatis-增删改查
1.创建Maven项目,项目名称mybatisdemo1,目录结构如图所示
2.pom.xml中配置内容如下
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.mycompany</groupId> <artifactId>mybatisdemo1</artifactId> <version>0.0.1-SNAPSHOT</version> <build/> <dependencies> <!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core --> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>2.7</version> </dependency> <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.4.1</version> </dependency> <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.39</version> </dependency> <!-- https://mvnrepository.com/artifact/junit/junit --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> </dependency> </dependencies> </project>
3.在src/main/java目录创建实体类StudentBean,包名(com.mycompany.beans),目录结构如下
4.实体类StudentBean的内容如下
package com.mycompany.beans;
public class StudentBean {
private Integer sid;
private String name;
public StudentBean() {
super();
}
public StudentBean(String name) {
super();
this.name = name;
}
public StudentBean(Integer sid, String name) {
super();
this.sid = sid;
this.name = name;
}
public Integer getSid() {
return sid;
}
public void setSid(Integer sid) {
this.sid = sid;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String toString() {
return "StudentBean [sid="+sid+",name="+name+"]";
}
}5.在src/main/java下创建接口StudentMapper,包名(com.mycompany.mapper)目录结构如下
6.接口StudentMapperr的内容如下
package com.mycompany.mapper;
import java.util.List;
import com.mycompany.beans.StudentBean;
public interface StudentMapper {
/**
* 新增用户
* @param student
* @return
* @throws Exception
*/
public int insertStudent(StudentBean student) throws Exception;
/**
* 修改用户
* @param student
* @param sid
* @return
* @throws Exception
*/
public int updateStudent(StudentBean student) throws Exception;
/**
* 删除用户
* @return
* @throws Exception
*/
public int deleteStudent(int sid) throws Exception;
/**
* 根据ID查询学生信息
* @return
* @throws Exception
*/
public StudentBean selectStudentById(int sid) throws Exception;
/**
* 查询所有的学生信息
* @return
* @throws Exception
*/
public List<StudentBean> selectAllStudent() throws Exception;
}7.在src/main/java下创建映射文件StudentMapper.xml,包名(com.mycompany.mapper),目录结构如下
8.映射文件StudentMapper.xml的内容如下
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org/DTD Mapper 3.0" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.mycompany.mapper.StudentMapper">
<!--
添加学生信息
在各种标签中的id属性必须和接口中的方法名相同 ， id属性值必须是唯一的，不能够重复使用。
parameterType属性指明查询时使用的参数类型，resultType属性指明查询返回的结果集类型
-->
<insert id="insertStudent" useGeneratedKeys="true" keyProperty="sid">
INSERT INTO student (name) VALUES (#{name})
</insert>
<!-- 修改学生信息 -->
<update id="updateStudent" parameterType="com.mycompany.beans.StudentBean">
UPDATE student SET name = #{name} WHERE sid = #{sid}
</update>
<!-- 删除学生信息 -->
<delete id="deleteStudent" parameterType="int">
DELETE FROM student WHERE sid=#{sid}
</delete>
<!-- 根据ID查询学生信息 -->
<select id="selectStudentById" parameterType="int" resultMap="studentMap">
SELECT * FROM student WHERE sid=#{sid}
</select>
<!-- 查询所有学生信息 -->
<select id="selectAllStudent" resultMap="studentMap">
SELECT * FROM student
</select>
<resultMap type="StudentBean" id="studentMap">
<id property="sid" column="sid" javaType="java.lang.Integer"/>
<result property="name" column="name" javaType="java.lang.String"/>
</resultMap>
</mapper>9.在src/main/java下创建工具类DBUtils,包名(com.mycompany.util)目录结构如下
10.工具类DBUtils的内容如下
package com.mycompany.util;
import java.io.IOException;
import java.io.Reader;
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 DBUtils {
public static SqlSessionFactory sessionFactory;
static{
try {
Reader reader = Resources.getResourceAsReader("mybatis.cfg.xml");
sessionFactory = new SqlSessionFactoryBuilder().build(reader);
} catch (IOException e) {
e.printStackTrace();
}
}
public static SqlSession getSession(){
return sessionFactory.openSession();
}
}11.在src/main/resources下创建mysql.properties属性文件,目录结构如下
12.mysql.properties属性文件内容如下
jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/test jdbc.username=root jdbc.password=
13.在src/main/resources下创建mybatis配置文件mybatis.cfg.xml,目录结构如下
14.配置文件mybatis.cfg.xml的内容如下
<?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>
<!-- 引入外部配置文件 -->
<properties resource="mysql.properties"></properties>
<typeAliases>
<package name="com.mycompany.beans"/>
</typeAliases>
<!-- 配置mybatis运行环境 -->
<environments default="mybatis">
<environment id="mybatis">
<!-- type="JDBC" 代表使用JDBC的提交和回滚来管理事务 -->
<transactionManager type="JDBC" />
<!-- mybatis提供了3种数据源类型，分别是：POOLED,UNPOOLED,JNDI -->
<!-- POOLED 表示支持JDBC数据源连接池 -->
<!-- UNPOOLED 表示不支持数据源连接池 -->
<!-- JNDI 表示支持外部数据源连接池 -->
<dataSource type="POOLED">
<property name="driver" value="http://www.mamicode.com/${jdbc.driver}" />
<property name="url" value="http://www.mamicode.com/${jdbc.url}" />
<property name="username" value="http://www.mamicode.com/${jdbc.username}" />
<property name="password" value="http://www.mamicode.com/${jdbc.password}" />
</dataSource>
</environment>
</environments>
<mappers>
<package name="com/mycompany/mapper"/>
</mappers>
</configuration>15.在src/main/java下创建StudentService文件,包名(com.mycompany.service),目录结构如下
16.StudentService文件的内容如下
package com.mycompany.service;
import java.util.List;
import org.apache.ibatis.session.SqlSession;
import com.mycompany.beans.StudentBean;
import com.mycompany.mapper.StudentMapper;
import com.mycompany.util.DBUtils;
public class StudentService {
/**
* 添加学生信息
* @param student
*/
public void insertStudent(StudentBean student){
SqlSession session = DBUtils.getSession();
StudentMapper mapper = session.getMapper(StudentMapper.class);
try {
int result = mapper.insertStudent(student);
System.out.println(result);
session.commit();
} catch (Exception e) {
e.printStackTrace();
session.rollback();
}
}
/**
* 修改学生信息
* @param student
*/
public void updateStudent(StudentBean student){
SqlSession session = DBUtils.getSession();
StudentMapper mapper = session.getMapper(StudentMapper.class);
try {
int result = mapper.updateStudent(student);
System.out.println(result);
session.commit();
} catch (Exception e) {
e.printStackTrace();
session.rollback();
}
}
/**
* 删除学生信息
* @param sid
*/
public void deleteStudent(int sid){
SqlSession session = DBUtils.getSession();
StudentMapper mapper = session.getMapper(StudentMapper.class);
try {
int result = mapper.deleteStudent(sid);
System.out.println(result);
session.commit();
} catch (Exception e) {
e.printStackTrace();
session.rollback();
}
}
/**
* 根据ID查询学生信息
* @param sid
*/
public void selectStudentById(int sid){
SqlSession session = DBUtils.getSession();
StudentMapper mapper = session.getMapper(StudentMapper.class);
try {
StudentBean student = mapper.selectStudentById(sid);
System.out.println(student);
session.commit();
} catch (Exception e) {
e.printStackTrace();
session.rollback();
}
}
/**
* 查询所有学生信息
*/
public void selectAllStudent(){
SqlSession session = DBUtils.getSession();
StudentMapper mapper = session.getMapper(StudentMapper.class);
try {
List<StudentBean> students = mapper.selectAllStudent();
for (StudentBean studentBean : students) {
System.out.println(studentBean);
}
session.commit();
} catch (Exception e) {
e.printStackTrace();
session.rollback();
}
}
}17.在src/test/java下创建StudentServiceTest测试类,包名(com.mycompany.service)目录结构如下
18.StudentServiceTest测试类的内容如下
package com.mycompany.service;
import org.junit.Test;
import com.mycompany.beans.StudentBean;
public class StudentServiceTest {
/**
* 测试添加学生信息操作
*/
@Test
public void insertStudentTest(){
StudentService studentService = new StudentService();
StudentBean student = new StudentBean("test insert");
studentService.insertStudent(student);
}
/**
* 测试修改学生信息操作
*/
@Test
public void updateStudent(){
StudentService studentService = new StudentService();
StudentBean studentBean = new StudentBean(5,"test update");
studentService.updateStudent(studentBean);
}
/**
* 测试删除学生信息操作
*/
@Test
public void deleteStudent(){
StudentService studentService = new StudentService();
studentService.deleteStudent(7);
}
/**
* 测试根据ID查询学生信息
*/
@Test
public void selectStudentById(){
StudentService studentService = new StudentService();
studentService.selectStudentById(8);
}
/**
* 测试查询所有学生信息
*/
@Test
public void selectAllStudent(){
StudentService studentService = new StudentService();
studentService.selectAllStudent();
}
}
本文出自 “素颜” 博客，谢绝转载！
MyBatis-增删改查
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