SpringBoot系列（二十八）MyBatisPlus级联操作

一、级联插入数据(无事务版本)

1.1、创建BannerDTO和BannerItemDTO

package io.github.talelin.latticy.dto;

import lombok.Getter;
import lombok.Setter;
import org.hibernate.validator.constraints.Length;

import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;
import java.util.List;

@Getter
@Setter
public class BannerDTO {

    @NotBlank
    @Length(min = 2, max = 20)
    private String name;

    @Length(min = 2, max = 30)
    private String title;

    private Integer version;

    @Length(min = 2, max = 256)
    private String img;

    @Length(min = 2, max = 256)
    private String description;

    @NotNull
    private List<BannerItemDTO> bannerItems;
}

package io.github.talelin.latticy.dto;

import lombok.Data;
import org.hibernate.validator.constraints.Length;

import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Positive;


@Data
public class BannerItemDTO {

//    @NotBlank
    @Length(min = 1, max = 255)
    private String img;

    @Length(min = 1, max = 255)
    private String name;

//    @NotNull
    @Positive
    private Integer type;

    @NotNull
    @Positive
    private Integer bannerId;

    @Length(min = 1, max = 50)
    private String keyword;

}

1.2、创建BannerBO和BannerItemBO

    package io.github.talelin.latticy.model;

    import com.baomidou.mybatisplus.annotation.*;
    import com.fasterxml.jackson.annotation.JsonIgnore;
    import lombok.Getter;
    import lombok.Setter;

    import java.util.Date;
    import java.util.List;

    @Getter
    @Setter
    @TableName("banner")
    public class BannerDO {
        @TableId(value = "id", type = IdType.AUTO)
        private Integer id;

        private String name;

        private String title;

        private String description;

        private String img;

        @Version
        private Integer version;

        @JsonIgnore
        private Date createTime;

        @JsonIgnore
        private Date updateTime;

        /*　@TableLogic注解参数
    　　　　value = "" 默认的原值
    　　　　delval = "" 删除后的值
    　　　　@TableLogic(value="原值",delval="改值")
        * */
        @JsonIgnore
        @TableLogic
        private Date deleteTime;
        //假设我们需要查询一个banner及其下面的item，首先对 Banner 实体类稍作修改，增加 bannerItemList 集合属性
        @TableField(exist = false)
        private List<BannerItemDO> items;
    }

package io.github.talelin.latticy.model;

import com.baomidou.mybatisplus.annotation.*;
import com.fasterxml.jackson.annotation.JsonIgnore;
import lombok.Data;
import lombok.Getter;
import lombok.Setter;

import java.util.Date;
import java.util.Objects;

@TableName("banner_item")
@Getter
@Setter
@Data
public class BannerItemDO extends BaseModel {

    private String name;
    
    private String img;

    private String keyword;

    private Integer type;

    private Integer bannerId;

}

1.3、创建BannerMapper和BannerItemMapper

package io.github.talelin.latticy.mapper;

import com.baomidou.mybatisplus.core.conditions.Wrapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.core.toolkit.Constants;
import io.github.talelin.latticy.model.BannerDO;
import org.apache.ibatis.annotations.*;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface BannerMapper extends BaseMapper<BannerDO> {
}

package io.github.talelin.latticy.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import io.github.talelin.latticy.model.BannerItemDO;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Repository;

import java.io.Serializable;
import java.util.List;

@Repository
public interface BannerItemMapper extends BaseMapper<BannerItemDO> {

}

1.4、创建BannerService

    public void create(BannerDTO bannerDTO) {
        BannerDO bannerDO = new BannerDO();
        BeanUtils.copyProperties(bannerDTO, bannerDO);
        bannerMapper.insert(bannerDO);

        List<BannerItemDTO> bannerItemDTO = bannerDTO.getBannerItems();

        bannerItemDTO.forEach(
            s->{
                BannerItemDO bannerItemDO = new BannerItemDO();
                BeanUtils.copyProperties(s, bannerItemDO);
                bannerItemDO.setBannerId(bannerDO.getId());
                bannerItemMapper.insert(bannerItemDO);
            }
        );
    }

1.5、BannerController

    @PostMapping("/createBanner")
    public CreatedVO create(@RequestBody @Validated BannerDTO dto) {
        bannerService.create(dto);
        return new CreatedVO();
    }

级联新增成功。

二、级联插入数据(事务版本)

三、级联删除数据 (无事务版本)

3.1、创建BannerDTO和BannerItemDTO

3.2、创建BannerBO和BannerItemBO

3.3、创建BannerMapper和BannerItemMapper

3.4、创建BannerService

public void deleteWithItem(Integer id) {
        BannerDO banner = bannerMapper.selectById(id);
        if (banner == null) {
            throw new NotFoundException(20000);
        }

        bannerMapper.deleteById(id);

        LambdaQueryWrapper<BannerItemDO> wrapper = new LambdaQueryWrapper<>();
        wrapper.eq(BannerItemDO::getBannerId, id);
        bannerItemMapper.delete(wrapper);

    }

3.5、BannerController

@DeleteMapping("/deleteBannerWithItem/{id}")
public DeletedVO deleteWithItem(@PathVariable @Positive Integer id) {
    bannerService.deleteWithItem(id);
    return new DeletedVO();
}