Eloquent 模型继承层次结构

Question

我有一个案例，其中 2 个 eloquent 模型应该从一个 User 模型继承属性，但 User 本身不应该作为独立实例存在。 （导师和学生，都继承自 User 类）。所以我目前正在做的是：

<?php

namespace App;

use Illuminate\Notifications\Notifiable;
use Illuminate\Foundation\Auth\User as Authenticatable;

abstract class User extends Authenticatable
{
    use Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'name', 'email', 'password',
    ];

    /**
     * The attributes that should be hidden for arrays.
     *
     * @var array
     */
    protected $hidden = [
        'password', 'remember_token',
    ];

    /**
     * Get the courses that the user has enrolled into
     *
     * @return \Illuminate\Database\Eloquent\Relations\HasMany
     */

    public function courses()
    {
        return $this->hasMany('App\Models\Course', 'user_course', 'user_id', 'course_id');
    }
}

class Student extends User
{
    protected $table = 'students';

    /**
     * Get the mentors that the user has hired
     *
     * @return \Illuminate\Database\Eloquent\Relations\HasMany
     */

    public function mentors()
    {
        return $this->hasMany('App\Models\User');
    }
}

class Mentor extends User
{
    protected $table = 'mentors';

    /**
     * Get a list of courses that a mentor is teaching
     *
     * @return \Illuminate\Database\Eloquent\Relations\HasMany
     */

    public function ownCourses()
    {
        return $this->hasMany('App\Models\Course', 'mentor_course', 'mentor_id', 'course_id');
    }
}

我想知道这样做是否正确？

Answer 1

恕我直言，我将使用polymorhic relation：

使用三个表：users、students和mentors；在users 表中添加两个字段：userable_id (integer)、userable_type (string)。

用户模型

class class User extends Authenticatable
{
    public function userable()
    {
        return $this->morphTo();
    }

学生模型：

class Student extends Model
{
    public function user()
    {
        return $this->morphOne('App\User', 'userable');
    }

导师模型：

class Mentor extends Model
{
    public function user()
    {
        return $this->morphOne('App\User', 'userable');
    }

现在User::find($id)->userable 根据 userable_type 的值返回一个 Student 或 Mentor 对象

我把其他的关系留给你，我希望这会有所帮助。