【MyBatis】初步解析MyBatis：实现数据库交互与关系映射的全面指南

spring:
  datasource:
    url: jdbc:mysql://127.0.0.1:3306/java_blog_spring?characterEncoding=utf8&useSSL=false
    username: root
    password: 232122
    driver-class-name: com.mysql.cj.jdbc.Driver
  mvc:
    favicon:
      enable: false
  profiles:  
    active: dev
mybatis:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    map-underscore-to-camel-case: true
logging:
  file:
    name: logs/springboot.log
  logback:
    rollingpolicy:
      max-file-size: 1KB
      file-name-pattern: ${LOG_FILE}.%d{yyyy-MM-dd}.%i
  level:
    com:
      example:
        demo: debug

#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://127.0.0.1:3306/mybatis_test?characterEncoding=utf8&useSSL=false
#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

-- 创建数据库
DROP DATABASE IF EXISTS mybatis_test;
CREATE DATABASE mybatis_test DEFAULT CHARACTER SET utf8mb4;
-- 使用数据数据
USE mybatis_test;
-- 创建表[用户表]
DROP TABLE IF EXISTS userinfo;
CREATE TABLE `userinfo` (
`id` INT ( 11 ) NOT NULL AUTO_INCREMENT,
`username` VARCHAR ( 127 ) NOT NULL,
`password` VARCHAR ( 127 ) NOT NULL,
`age` TINYINT ( 4 ) NOT NULL,
`gender` TINYINT ( 4 ) DEFAULT '0' COMMENT '1-男 2-⼥ 0-默认',
`phone` VARCHAR ( 15 ) DEFAULT NULL,
`delete_flag` TINYINT ( 4 ) DEFAULT 0 COMMENT '0-正常, 1-删除',
`create_time` DATETIME DEFAULT now(),
`update_time` DATETIME DEFAULT now(),
PRIMARY KEY ( `id` )
) ENGINE = INNODB DEFAULT CHARSET = utf8mb4;
-- 添加用户信息
INSERT INTO mybatis_test.userinfo ( username, `password`, age, gender, phone )
VALUES ( 'admin', 'admin', 18, 1, '18612340001' );
INSERT INTO mybatis_test.userinfo ( username, `password`, age, gender, phone )
VALUES ( 'zhangsan', 'zhangsan', 18, 1, '18612340002' );
INSERT INTO mybatis_test.userinfo ( username, `password`, age, gender, phone )
VALUES ( 'lisi', 'lisi', 18, 1, '18612340003' );
INSERT INTO mybatis_test.userinfo ( username, `password`, age, gender, phone )
VALUES ( 'wangwu', 'wangwu', 18, 1, '18612340004' );

import lombok.Data;
import java.util.Date;
@Data
public class UserInfo {
  private Integer id;
  private String username;
  private String password;
  private Integer age;
  private Integer gender;
  private String phone;
  private Integer deleteFlag;
  private Date createTime;
  private Date updateTime;
}

import com.example.demo.model.UserInfo;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import java.util.List;
@Mapper
public interface UserInfoMapper {
  //查询所有用户
  @Select("select username, `password`, age, gender, phone from userinfo")
  public List<UserInfo> queryAllUser();
}

import com.example.demo.model.UserInfo;
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//注意,此处的SpringBootTest必须填上,它是为了引入前面所写代码引入的注解
class UserInfoMapperTest {
  @Autowired
  private UserInfoMapper userInfoMapper;
  
  @Test
  void queryAllUser() {
    List<UserInfo> userInfoList = userInfoMapper.queryAllUser();
    System.out.println(userInfoList);
  }
}