Laravel 10+MongoDB下Sanctum生成Token遇prepare() on null错误

问题描述 #

我有一个使用MongoDB数据库的Laravel 10应用，正在为api_users集合中的用户创建生成Token的API端点。创建用户的函数运行完全正常，但调用createToken生成Token时触发错误。

创建用户的正常代码 #

public function createApiUser(Request $request)
{
    $username = $request->input('username');
    $password = $request->input('password');

    $password = Hash::make($password);

    $apiUser = new ApiUser();

    $apiUser->username = $username;
    $apiUser->password = $password;

    try {
        $apiUser->save();
        return ["Success"];
    } catch (\Throwable $th) {
        return ["error" => $th->getMessage()];
    }
}

生成Token的报错代码 #

public function generateToken(Request $request)
{
    $username = $request->input('username');
    $password = $request->input('password');
    $collection = DB::connection('mongodb')->collection('api_users');

    // 根据用户名获取用户文档
    $userData = ApiUser::where('username', $username)->first();

    if ($userData && Hash::check($password, $userData['password'])) {
        $user = $userData;
        // 执行此行时触发错误
        $token = $user->createToken('MyApp')->plainTextToken;

        return response()->json([
            'token' => $token,
            'user' => $user,
        ], 200);
    }

    return response()->json(['error' => 'Unauthorised'], 401);
}

错误信息 #

Error: Call to a member function prepare() on null in file /vendor/laravel/framework/src/Illuminate/Database/Connection.php on line 574

ApiUser模型代码 #

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use MongoDB\Laravel\Eloquent\Model as Eloquent;
use MongoDB\Laravel\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;
use Illuminate\Database\Eloquent\Model;
use Laravel\Sanctum\HasApiTokens;

class ApiUser extends Eloquent
{
    use HasApiTokens, HasFactory,Notifiable;
    protected $guard = 'api';
    protected $table = 'api_users';
    protected $connection = 'mongodb';
    protected $guarded = [];

    protected $fillable = [
        'username', 'password',
    ];
}

auth.php配置 #

<?php

return [ 
    'defaults' => [
        'guard' => 'web',
        'passwords' => 'users',
        'email' => [
            'driver' => 'session',
            'provider' => 'users',
        ],
    ], 

    'guards' => [
        'web' => [
            'driver' => 'session',
            'provider' => 'users',
        ],
        'mongodb' => [
            'driver' => 'session',
            'provider' => 'users',
        ],
        'api' => [
            'driver' => 'sanctum',
            'provider' => 'api_users',
        ],
        'api_users' => [
            'driver' => 'sanctum',
            'provider' => 'api_users',
        ],
    ],

    'verification' => [
        'enabled' => false,
        'expire' => 60,
    ], 

    'providers' => [
        'users' => [
            'driver' => 'eloquent',
            'model' => App\Models\User::class,
        ],
        'api_users' => [
            'driver' => 'eloquent',
            'model' => App\Models\ApiUser::class,
        ],
    ],
 
    'passwords' => [
        'users' => [
            'provider' => 'users',
            'table' => 'password_resets',
            'expire' => 60,
            'throttle' => 60,
        ],
    ],
 
    'password_timeout' => 10800,
];

解决方案 #

问题根源 #

错误是因为Laravel Sanctum默认使用默认数据库连接（通常为MySQL）存储Token，但你的ApiUser模型使用MongoDB连接，导致Sanctum尝试用错误的连接操作Token表。

修复步骤 #

1. 修正ApiUser模型继承关系
   移除多余的模型引用，直接继承MongoDB提供的Authenticatable类，确保认证契约正确实现：

   <?php
   
   namespace App\Models;
   
   use Illuminate\Database\Eloquent\Factories\HasFactory;
   use MongoDB\Laravel\Auth\User as Authenticatable;
   use Illuminate\Notifications\Notifiable;
   use Laravel\Sanctum\HasApiTokens;
   
   class ApiUser extends Authenticatable
   {
       use HasApiTokens, HasFactory, Notifiable;
   
       protected $guard = 'api';
       protected $table = 'api_users';
       protected $connection = 'mongodb';
       protected $guarded = [];
   
       protected $fillable = [
           'username', 'password',
       ];
   }
   

2. 配置Sanctum使用MongoDB连接
   发布Sanctum配置文件（如果未发布）：

   php artisan vendor:publish --provider="Laravel\Sanctum\SanctumServiceProvider"
   

   在config/sanctum.php中指定数据库连接为mongodb：

   return [
       // 其他配置...
       'database_connection' => env('SANCTUM_DB_CONNECTION', 'mongodb'),
       // 其他配置...
   ];
   

3. 确保MongoDB连接配置正确
   检查.env文件中的MongoDB连接参数：

   DB_CONNECTION=mongodb
   DB_HOST=127.0.0.1
   DB_PORT=27017
   DB_DATABASE=your_database_name
   DB_USERNAME=
   DB_PASSWORD=
   

4. 重新生成Sanctum迁移（可选）
   如果之前用MySQL创建过Sanctum迁移，删除相关文件后运行MongoDB迁移：

   php artisan mongodb:migrate
   

5. 简化generateToken方法
   优化代码，直接使用模型查询：

   public function generateToken(Request $request)
   {
       $request->validate([
           'username' => 'required',
           'password' => 'required',
       ]);
   
       $user = ApiUser::where('username', $request->username)->first();
   
       if (!$user || !Hash::check($request->password, $user->password)) {
           return response()->json(['error' => 'Unauthorised'], 401);
       }
   
       $token = $user->createToken('MyApp')->plainTextToken;
   
       return response()->json([
           'token' => $token,
           'user' => $user,
       ], 200);
   }
   

内容的提问来源于stack exchange，提问作者bob269