概览

MyBatis简介

ORM模型

Hibernate

JPA

MyBatis

什么时候用MyBatis

Mybatis-Plus代码生成器

视频讲解：https://space.bilibili.com/483260422
生鱼忧患、死鱼安乐

Generator源码地址

Github：https://github.com/baomidou/generator
Gitee：https://gitee.com/baomidou/generator

Maven仓库坐标：https://search.maven.org/search?q=mybatis-plus-generator
官方文档：https://baomidou.com/guide/generator-new.html

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构建者模式（Builder Pattern）

�示例源码

Github: https://github.com/baomidou/mybatis-plus-generator-examples
Gitee: https://gitee.com/baomidou/mybatis-plus-generator-examples\

代码
show table status where 1=1;

show full fields from user;
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常用架构设计

ExpertWrapperImpl类如何设计实现dto、toEntity自动转换

package com.innovation.scene.service.wrapper;
import java.util.List;
/**
* 实体和DTO之间的统一的映射转换接口
*
* @author zhongying
* @since 2020/07/06
*/
public interface EntityWrapper<D, E> {
    /**
    * dto
    * @param dto
    * @return
    */
    E toEntity(D dto);
    /**
    * entity
    * @param entity
    * @return
    */
    D toDto(E entity);
    /**
    * dtoList
    * @param dtoList
    * @return
    */
    List<E> toEntity(List<D> dtoList);
    /**
    * entityList
    * @param entityList
    * @return
    */
    List<D> toDto(List<E> entityList);
}

专家模块

package com.innovation.scene.service.wrapper;
import com.innovation.scene.domain.Expert;
import com.innovation.scene.domain.Scene;
import com.innovation.scene.service.dto.ExpertDTO;
import com.innovation.scene.service.dto.SceneDTO;
/**
 * 实体{@link Scene}和它的DTO{@link SceneDTO}之间的映射转换
 * 编译时会自动生成实现类，可以不用@Mapper，自定义实现接口
 *
 * @author jiadp
 * @since 2022/04/20
 */
public interface ExpertWrapper extends EntityWrapper<ExpertDTO, Expert> {
    /**
     * id
     *
     * @param id
     * @return
     */
    default Expert fromId(Long id) {
        if (id == null) {
            return null;
        }
        Expert expert = new Expert();
        expert.setId(id);
        return expert;
    }
}

专家模块接口实现

package com.innovation.scene.service.wrapper;
import com.innovation.scene.domain.Expert;
import com.innovation.scene.service.dto.ExpertDTO;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Component;
import java.util.ArrayList;
import java.util.List;
/**
 * @author jiadp
 * @since 2022/04/20
 */
@RequiredArgsConstructor
@Component
public class ExpertWrapperImpl implements ExpertWrapper {
    @Override
    public Expert toEntity(ExpertDTO dto) {
        if (dto == null) {
            return null;
        }
        Expert expert = new Expert();
        expert.setId(dto.getId());
        expert.setUserId(dto.getUserId());
        expert.setInContributionDegree(dto.getInContributionDegree());
        expert.setInTime(dto.getInTime());
        expert.setBio(dto.getBio());
        expert.setStatus(dto.getStatus());
        expert.setApprovalStatus(dto.getApprovalStatus());
        expert.setApproveUserId(dto.getApproveUserId());
        expert.setCreateUser(dto.getCreateUser());
        expert.setCreateTime(dto.getCreateTime());
        expert.setUpdateUser(dto.getUpdateUser());
        expert.setUpdateTime(dto.getUpdateTime());
        expert.setWorkUnit(dto.getWorkUnit());
        expert.setPost(dto.getPost());
        expert.setTitle(dto.getTitle());
        expert.setBusinessArea(dto.getBusinessArea());
        expert.setMainScenes(dto.getMainScenes());
        expert.setAwardResume(dto.getAwardResume());
        expert.setImage(dto.getImage());
        return expert;
    }
    @Override
    public ExpertDTO toDto(Expert entity) {
        if (entity == null) {
            return null;
        }
        ExpertDTO expertDto = new ExpertDTO();
        expertDto.setId(entity.getId());
        expertDto.setUserId(entity.getUserId());
        expertDto.setInContributionDegree(entity.getInContributionDegree());
        expertDto.setInTime(entity.getInTime());
        expertDto.setBio(entity.getBio());
        expertDto.setStatus(entity.getStatus());
        expertDto.setApprovalStatus(entity.getApprovalStatus());
        expertDto.setApproveUserId(entity.getApproveUserId());
        expertDto.setCreateUser(entity.getCreateUser());
        expertDto.setCreateTime(entity.getCreateTime());
        expertDto.setUpdateUser(entity.getUpdateUser());
        expertDto.setUpdateTime(entity.getUpdateTime());
        expertDto.setWorkUnit(entity.getWorkUnit());
        expertDto.setPost(entity.getPost());
        expertDto.setTitle(entity.getTitle());
        expertDto.setBusinessArea(entity.getBusinessArea());
        expertDto.setMainScenes(entity.getMainScenes());
        expertDto.setAwardResume(entity.getAwardResume());
        expertDto.setImage(entity.getImage());
        return expertDto;
    }
    @Override
    public List<Expert> toEntity(List<ExpertDTO> dtoList) {
        if (dtoList == null) {
            return null;
        }
        List<Expert> list = new ArrayList<Expert>(dtoList.size());
        for (ExpertDTO expertDto : dtoList) {
            list.add(toEntity(expertDto));
        }
        return list;
    }
    @Override
    public List<ExpertDTO> toDto(List<Expert> entityList) {
        if (entityList == null) {
            return null;
        }
        List<ExpertDTO> list = new ArrayList<ExpertDTO>(entityList.size());
        for (Expert expert : entityList) {
            list.add(toDto(expert));
        }
        return list;
    }
}