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新建

idea

准备

数据库

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');

pojo.User

package com.t0.mybatis_mysql.pojo;

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


    public User() {
    }

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

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

配置mybatis

连接数据库

spring.application.name=mybatis_mysql
#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/db03
#db03是连接名下的数据库
#连接数据库的用户名
spring.datasource.username=www123
#连接数据库的密码
spring.datasource.password=www123

测试

package com.t0.mybatis_mysql.mapper;


import com.t0.mybatis_mysql.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

import java.util.List;

@Mapper
public interface UserMapper {
    @Select("select * from user")
    public List<User> list();
}

package com.t0.mybatis_mysql;

import com.t0.mybatis_mysql.mapper.UserMapper;
import com.t0.mybatis_mysql.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 MybatisMysqlApplicationTests {

    @Autowired
    private UserMapper userMapper;

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

}

 运行

SQL命令提示

2023版本自带，应该2024也有

数据库连接池

容器

Lombok

在pom.xml引入依赖

<!--        引入Lombok依赖-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <scope>provided</scope>
        </dependency>

或者直接@Data 在引入依赖。

@Data
@NoArgsConstructor
@AllArgsConstructor

Data不包含无参构造和全参构造。

注解	作用
@Getter/@Setter	提供get/set方法
@ToString	tosString方法
@EqualsAndHashCode	自动重写equals方法和hashCode方法
@Data	提供@Getter+@Setter+@ToString+@EqualsAndHashCode
@NoArgsConstructor	无参构造
@AllArgsConstructor	全参构造