Mybatis入门项目

目录

Mybatis入门项目

数据库

pom.xml

logback.xml

mybatis-config.xml

userMapper.xml

User类

MybatisDemo 测试类

---

数据库

创建好一个mybatis数据库，数据库中创建表tb_user表，加几条数据。

create database mybatis;
use mybatis;

DROp TABLE IF EXISTS `tb_user`;

CREATE TABLE tb_user(
  id int primary key auto_increment,
  username varchar(20),
  password varchar(20),
  gender char(1),
  addr varchar(30),
);

INSERT INTO `tb_user` VALUES (1, 'zhangsan', '123', '男', '北京');
INSERT INTO `tb_user` VALUES (2, '李四', '234', '女', '天津');
INSERT INTO `tb_user` VALUES (3, '王五', '11', '男', '西安');

pom.xml

创建maven项目，在pom.xml配置文件下配置依赖。

    
    
        org.mybatis
        mybatis
        3.5.5
    

    
    
        mysql
        mysql-connector-java
        5.1.46
    

    
    
        junit
        junit
        4.13
        test
    

    
    
        org.slf4j
        slf4j-api
        1.7.20
    
    
    
        ch.qos.logback
        logback-classic
        1.2.3
    
    
    
        ch.qos.logback
        logback-core
        1.2.3
    

logback.xml

在项目的resources目录下创建logback.xml配置文件

    
    
        
            [%level]%blue(%d{HH:mm:ss.SSS})%cyan([%thread])%boldGreen(%logger{15}) - %msg %n
        
    

    
        
    

mybatis-config.xml

编写 MyBatis 核心配置文件

userMapper.xml

编写 SQL 映射文件

 

    
        select * from tb_user;
    

User类

在src的Java目录下创建com.yozi.pojo.User

package com.yozi.pojo;

public class User {
    private Integer id;
    private String username;
    private String password;
    private String gender;
    private String addr;

    public Integer getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public String getAddr() {
        return addr;
    }

    public void setAddr(String addr) {
        this.addr = addr;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + ''' +
                ", password='" + password + ''' +
                ", gender='" + gender + ''' +
                ", addr='" + addr + ''' +
                '}';
    }
}

MybatisDemo 测试类

在com.yozi下创建MybatisDemo类

public class MyBatisDemo {

    public static void main(String[] args) throws IOException {
        //1. 加载mybatis的核心配置文件，获取 SqlSessionFactory
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

        //2. 获取SqlSession对象，用它来执行sql
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //3. 执行sql
        List users = sqlSession.selectList("test.selectAll"); //参数是一个字符串，该字符串必须是映射配置文件的namespace.id
        System.out.println(users);
        //4. 释放资源
        sqlSession.close();
    }
}