SpringBoot图文并茂详解如何引入mybatis与连接Mysql数据库【mysql优化】

目录

• 创建一个SpringBoot项目
• 创建mysql表
• 编写实体类
• 配置Mapper
• 感叹

CREATE TABLE sp_users(
	`id` INT PRIMARY KEY,
	`username` VARCHAR(30),
	`age` INT
);

INSERT INTO sp_users(id,`username`,`age`) VALUES(1,"张三",11);
INSERT INTO sp_users(id,`username`,`age`) VALUES(2,"李四",21);
INSERT INTO sp_users(id,`username`,`age`) VALUES(3,"游坦之",800); 

package com.you.domain;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;
@Data
@NoArgsConstructor
@AllArgsConstructor
@ToString
public class user {
    private int id;
    private String username;
    private int age;
}

package com.you.mapper;
import com.you.domain.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Repository;
import java.util.List;
@Mapper
@Repository
public interface UserMapper {
    @Select("select * from sp_users")
    public List findAll();
}

package com.you.boot;
import com.you.boot.domain.User;
import com.you.boot.mapper.UserMapper;
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 BootMybatis03ApplicationTests {
    @Autowired
    private UserMapper userMapper;
    @Test
    public void testFindAll()
    {
        List list = userMapper.findAll();
        System.out.println(list);
    }
}

    
        select * from sp_users
    

package com.you.boot.mapper;
import com.you.boot.domain.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;
import java.util.List;
@Mapper
@Repository
public interface UserXmlMapper {
    public List findAll();
}

package com.you.boot;
import com.you.boot.domain.User;
import com.you.boot.mapper.UserMapper;
import com.you.boot.mapper.UserXmlMapper;
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 BootMybatis03ApplicationTests {
    @Autowired
    private UserXmlMapper userXmlMapper;
    @Test
    public void testFindAll2()
    {
        List list = userXmlMapper.findAll();
        System.out.println(list);
    }
}