crm/app/model/UserCollect.php

<?php
namespace app\model;

use think\Model;

class UserCollect extends Model
{
    /**
     * 多态关联
     */
    public function content()
    {
        return $this->morphTo('content', [
            'materialCase'=>'app\model\MaterialCase',
            'talkskill'=>'app\model\Talkskill',
            'materialEvidence' => 'app\model\MaterialEvidence',
            'companyStrength' => 'app\model\CompanyStrength'
        ]);
    }
}