laravel9模型关联

一对一关联

表结构

用户表，头像表

users
id
nickname

avatars
id
user_id

定义模型

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    public function avatar()
    {
        return $this->hasOne(Avatar::class);
    }
}

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Avatar extends Model
{
    public function user()
    {
        return $this->belongsTo(User::class);
    }
}

一对多关联

表结构

用户表（同上）， 订单表

orders
id
user_id
no
title

定义模型

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class User extends Model
{
    public function orders()
    {
        return $this->hasMany(Order::class);
    }
}

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Order extends Model
{
    public function user()
    {
        return $this->belongsTo(User::class);
    }
}