09MP-SpringBoot+Mybatis+MP实现查询

1、引入依赖

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!--简化代码的工具包-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        
        **<!--mybatis-plus集成springboot的依赖-->**
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.3.3</version>
        </dependency>

        <!--mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <!--日志-->
        <dependency>
            <groupId>repository.org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.9</version>
        </dependency>
    </dependencies>

2、编写application.yml配置文件

3、引入log4j.properties的配置文件

log4j.rootLogger=DEBUG,A1
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=[%t] [%c]-[%p] %m%n

4、编写实体类

@Data
@AllArgsConstructor
@NoArgsConstructor
@TableName("tb_user")
public class User {
    private int id;
    private String user_name;
    private String password;
    private String name;
    private int age;
    private String email;
}

5、编写mapper接口

@Mapper
public interface UserMapper extends BaseMapper<User> {
}

6、在test文件夹中编写测试类

@SpringBootTest
class MpSpringbootApplicationTests {

    @Autowired
    private UserMapper userMapper;

    @Test
    void contextLoads() {
        List<User> list = userMapper.selectList(null);
        for (User user : list) {
            System.out.println(user);
        }

    }

}