Mybatis的使用CRUD

数据库

CREATE DATABASE mybatis;
USE mybatis;
CREATE TABLE USER(
	id INT PRIMARY KEY AUTO_INCREMENT NOT NULL,
	NAME VARCHAR(30) DEFAULT NULL,
	pwd VARCHAR(30) DEFAULT NULL
)ENGINE=INNODB DEFAULT CHARSET=utf-8;


INSERT INTO USER(id,NAME,pwd) VALUES
(1,"Levi.Zhao","123456"),
(2,"test","test"),
(3,"admin","admin"),
(4,"root","root");

UserDao.java

package top.withlevi.dao;

import top.withlevi.domain.User;

import java.util.List;

public interface UserDao {
    // 查询所有数据
    List<User> getUserList();

    // 查询某个数据
   User getUserById(int id);

   // 添加数据
    int addUser(User user);

   // 修改数据
   int updateUser(User user);

   // 删除数据
    int delUser(int id);
}

UserMapperDao.xml

<?xml version="1.0" encoding="UTF8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="top.withlevi.dao.UserDao">

<!--查询全部数据-->
    <select id="getUserList" resultType="top.withlevi.domain.User">
        select * from mybatis.user;
    </select>

<!--查询某个数据-->
    <select id="getUserById" parameterType="top.withlevi.domain.User" resultType="top.withlevi.domain.User">
        select * from mybatis.user where id = #{id};
    </select>

<!--添加数据-->
    <insert id="addUser" parameterType="top.withlevi.domain.User">
        insert into mybatis.user(id, name, pwd) values (#{id},#{name},#{pwd});
    </insert>

<!--修改数据-->
    <update id="updateUser" parameterType="top.withlevi.domain.User" >
        update mybatis.user set name=#{name},pwd=#{pwd} where id=#{id};
    </update>

<!--删除数据-->
<delete id="delUser" parameterType="int">
    delete from mybatis.user where id=#{id};
</delete>

</mapper>

User.java

package top.withlevi.domain;

public class User {
    private int id;
    private String name;
    private String pwd;

    public User() {
    }

    public User(int id, String name, String pwd) {
        this.id = id;
        this.name = name;
        this.pwd = pwd;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", pwd='" + pwd + '\'' +
                '}';
    }
}

MybatisUtils.java

package top.withlevi.utils;


import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

//sqlSessionFactory --> sqlSession
public class MybatisUtils {
    private static SqlSessionFactory sqlSessionFactory;
    static{
        String resource = "mybatis-config.xml";
        try {
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static  SqlSession getSqlSession(){
        return sqlSessionFactory.openSession();
    }

}

resources->mybatis-config.xml

<?xml version="1.0" encoding="UTF8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<!--configuration核心配置文件-->
<configuration>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="top/withlevi/dao/UserMapperDao.xml"></mapper>
    </mappers>
</configuration>

parent->pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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>

        <!--父工程-->
    <groupId>top.withlevi</groupId>
    <artifactId>Mybatis-Study</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>Mybatis-01</module>
    </modules>

    <!--导入依赖-->
    <dependencies>
        <!--mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.32</version>
        </dependency>
        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.5</version>
        </dependency>
        <!--junit-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <build>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>

            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>
</project>

kid->pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <parent>
        <artifactId>Mybatis-Study</artifactId>
        <groupId>top.withlevi</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>Mybatis-01</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

</project>

TestDao.java

package top.withlevi.test;

import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import top.withlevi.dao.UserDao;
import top.withlevi.domain.User;
import top.withlevi.utils.MybatisUtils;

import java.util.List;

public class TestDao {

    @Test
    public void Test01(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserDao mapper = sqlSession.getMapper(UserDao.class);
        List<User> userList = mapper.getUserList();
        for (User user : userList) {
            System.out.println(user);
        }
        sqlSession.close();
    }

    @Test
    public void Test02(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserDao mapper = sqlSession.getMapper(UserDao.class);
        User user = mapper.getUserById(3);
        System.out.println(user);
        sqlSession.close();
    }

    @Test
    public void Test03(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserDao mapper = sqlSession.getMapper(UserDao.class);
        int result = mapper.addUser(new User(5, "赵增印", "iBj@2021"));
        if (result>0){
            System.out.println("add successful....");
        }

        // 提交事务
        sqlSession.commit();
        sqlSession.close();
    }

    @Test
    public void Test04(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserDao mapper = sqlSession.getMapper(UserDao.class);
        int i = mapper.updateUser(new User(2, "cnbj", "hahhaha"));
        if (i>0){
            System.out.println("update successful...");
        }

        sqlSession.commit();
        sqlSession.close();
    }

    @Test
    public void Test05(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserDao mapper = sqlSession.getMapper(UserDao.class);
        int i = mapper.delUser(2);
        if (i>0){
            System.out.println("delete data successful...");
        }
        sqlSession.commit();
        sqlSession.close();
    }
}