MyBatis-Plus的简单使用案例

MyBatis-Plus的简单使用案例

gradle

dependencies {
    implementation ('org.springframework.boot:spring-boot-starter-web')
    runtimeOnly 'mysql:mysql-connector-java'
    testImplementation('org.springframework.boot:spring-boot-starter-test') {
        exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
    }
    compile 'com.baomidou:mybatis-plus-boot-starter:3.4.1'
}

配置

server.port=8081

spring.datasource.password=xxxxxx
spring.datasource.url=jdbc:mysql://ip:3306/mybatis_demo?useUnicode=true&characterEncoding=utf-8
spring.datasource.username=root

logging.level.com.study.mybatisplusdemo.user.mapper=debug

配置启动项

@SpringBootApplication
@MapperScan("com.study.mybatisplusdemo")
public class MybatisPlusDemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(MybatisPlusDemoApplication.class, args);
    }


    @Bean//分页插件
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import com.baomidou.mybatisplus.extension.handlers.JacksonTypeHandler;

import java.util.Arrays;

@TableName("m_user")
public class User {
    @TableId(value = "id",type= IdType.AUTO)
    private Integer id;
    @TableField("name")
    private String name;
    @TableField("age")
    private Integer age;
    //类型处理器,用于类型转换使用
    @TableField(value = "json",typeHandler = JacksonTypeHandler.class)
    private String[] json;

    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 Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String[] getJson() {
        return json;
    }

    public void setJson(String[] json) {
        this.json = json;
    }

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

public interface UserMapper extends BaseMapper<User> {
    @Select("select * from m_user where id=#{id}")
    public User findUser(int id);
}

@Service
public class UserService {
    @Autowired(required = false)
    private UserMapper userMapper;
	//使用Wrapper 进行查询 
    public User findUser(int id){
        // userMapper.findUser(id);
        //userMapper.selectById(id);
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.eq("id",id);
        User user = userMapper.selectOne(wrapper);
//        System.out.println(wrapper.getSqlSegment());
        return user;
    }


    public IPage<User> pageUser(int pageNum,int size){
        Page<User> page = new Page<>();
        page.setSize(size);
        page.setCurrent(pageNum);
        IPage<User> userIPage = this.userMapper.selectPage(page, null);
        System.out.println(userIPage);
        return userIPage;
    }
    //使用Wrapper 进行更新
    public User update(User user) {

        UpdateWrapper<User> wrapper = new UpdateWrapper<>();
        wrapper.set(!StringUtils.isEmpty(user.getName()),"name",user.getName());
        wrapper.set("age",user.getAge());
        wrapper.eq("id",user.getId());
        String sqlSet = wrapper.getSqlSet();
//        System.out.println(sqlSet);
        userMapper.update(null,wrapper);
        return null;
    }


}

@RequestMapping("/user")
@RestController
public class UserController {
    @Autowired
    private UserService userService;

    @RequestMapping("/user")
    public User getUser(int id){
        return userService.findUser(id);
    }

    @RequestMapping("/pageUser")
    public IPage<User> pageUser(int page,int size){
        return userService.pageUser(page,size);
    }

    @RequestMapping("update")
    public User updateUser(@RequestBody User user){
       return userService.update(user);

    }


}