Mybatis入门

目录

Mybatis简介

准备工作

Mybatis入门

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Mybatis简介

MyBatis 是一款优秀的持久层框架，它支持定制化SQL、存储过程以及高级映射，MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获得结果集。

准备工作

 创建SpringBoot工程 

注意勾选下面两种依赖

 点击finish完成工程的创建

  pom.xml文件内容如下

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        2.7.5
        
        
    
    com.itheima
    springboot-mybatis-quickstart
    0.0.1-SNAPSHOT
    springboot-mybatis-quickstart
    Demo project for Spring Boot
    
        11
    
    
        
        
            org.mybatis.spring.boot
            mybatis-spring-boot-starter
            2.2.2
        
        
        
            com.mysql
            mysql-connector-j
            runtime
        
        
        
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
    
    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

连接数据库

注意Database的名称，一会需要填到resources.application.properties文件中 

创建User表

create table user(
    id int unsigned primary key auto_increment comment 'ID',
    name varchar(100) comment '姓名',
    age tinyint unsigned comment '年龄',
    gender tinyint unsigned comment '性别, 1:男, 2:女',
    phone varchar(11) comment '手机号'
) comment '用户表';
insert into user(id, name, age, gender, phone) VALUES (null,'白眉鹰王',55,'1','18800000000');
insert into user(id, name, age, gender, phone) VALUES (null,'金毛狮王',45,'1','18800000001');
insert into user(id, name, age, gender, phone) VALUES (null,'青翼蝠王',38,'1','18800000002');
insert into user(id, name, age, gender, phone) VALUES (null,'紫衫龙王',42,'2','18800000003');
insert into user(id, name, age, gender, phone) VALUES (null,'光明左使',37,'1','18800000004');
insert into user(id, name, age, gender, phone) VALUES (null,'光明右使',48,'1','18800000005');

创建User类

目录结构如下

User.java内容如下

package com.hi1220.demo.pojo;

public class User {
    private Integer id;
    private String name;
    private short age;
    private short gender;
    private String phone;

    public User() {
    }

    public User(Integer id, String name, short age, short gender, String phone) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.phone = phone;
    }

    public Integer getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public short getAge() {
        return age;
    }

    public void setAge(short age) {
        this.age = age;
    }

    public short getGender() {
        return gender;
    }

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

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }
}

 在resources.application.properties文件中配置数据库的连接信息

#驱动类名称
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
#数据库连接的url
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis
#连接数据库的用户名
spring.datasource.username=root
#连接数据库的密码
spring.datasource.password=root

Mybatis入门

目录结构如下

 UserMapper.interface文件内容如下

package com.hi1220.demo.mapper;

import com.hi1220.demo.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import java.util.List;

@Mapper
public interface UserMapper {
    //查询全部用户信息

    @Select("select * from user")
    public List list ();

}

 test目录下的ApplicationTests.java文件内容如下

package com.hi1220.demo;

import com.hi1220.demo.mapper.UserMapper;
import com.hi1220.demo.pojo.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

@SpringBootTest
class DemoApplicationTests {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void testListUser(){
        List userList = userMapper.list();
        userList.stream().forEach(user -> {
            System.out.println(user);
        });
    }
}

运行结果如下