mapper
package mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;
import pojo.User;
@Mapper
public interface UserMapper extends BaseMapper<User> {
}
pojo
package pojo;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;
/**
* @author : Pj-Xk
* @date : 2023-02-19 14:12
**/
@Data
@TableName(value = "t_user")
public class User {
private int id;
private String username;
private String password;
private String photo;
}
测试
import mapper.UserMapper;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import pojo.User;
import java.util.List;
/**
* @author : Pj-Xk
* @date : 2023-02-19 14:38
**/
public class mapperTest {
@Autowired
UserMapper userMapper;
@Test
public void MapperTest() {
System.out.println("-------------1----------");
List users = userMapper.selectList(null);
System.out.println(users);
}
}
空指针异常
spring 测试