guangan/plugs/think-plugs-cms/src/model/CmsTutorial.php

<?php

namespace plugin\cms\model;

use think\admin\Model;

class CmsTutorial extends Model
{
    /**
     * 定义与分类的多对多关系
     */
    public function categories()
    {
        return $this->belongsToMany(CmsCategory::class, CmsTutorialCategory::class, 'cid', 'tid');
    }

    public function cateids()
    {
        return $this->hasMany(CmsTutorialCategory::class, 'tid');
    }
    /**
     * 获取分类ID列表
     */
    public function getCategoryIdsAttr()
    {
        return $this->categories()->column('id');
    }

    public function setCategoryIdsAttr($value)
    {
        if ($this->isExists()) {
            $this->categories()->detach();
            if (is_array($value)) {
                foreach ($value as $cid) {
                    $this->categories()->attach($cid);
                }
            }
        }
    }
}